Department Environmental Social Sciences

Decision Analysis (DA)

A group of people discussing a decision

Contact

PD Dr. Judit Lienert Group Leader, Group: DA Tel. +41 58 765 5574 Send Mail

The cluster Decision Analysis aims at achieving a better understanding of difficult environmental decision problems and at contributing to open research questions in Multi-Criteria Decision Analysis (MCDA). The focus lies on problem structuring of complex decisions, integrating stakeholder preferences into the decision process (including behavioral aspects), and dealing with uncertainty. A main aim is to simplify preference elicitation and decision making processes to facilitate their application in real world decision making without compromising on theoretical soundness.

The Decision Analysis cluster combines social, engineering, and natural science knowledge to support complex real world decision processes in aquatic science and technology. There is a close interaction with scientists from other disciplines at Eawag.

The empirical focus lies on urban water management (e.g. sustainable water infrastructure planning, decentralized systems), ecosystem services, and the preservation of water resources (e.g. river management). In transdiscipinary projects, stakeholders are integrated into research in different steps of the decision making process.

What is Multi-Criteria Decision Analysis (MCDA)?

Difficult decisions

Decision problems can be difficult if the decision makers hope to achieve several conflicting objectives. For example, one objective could be ‘low costs’ while another objective is to achieve ‘good environmental performance’. However, the most environmentally-friendly technical option might also be the most expensive one. In environmental decisions, typically multiple stakeholders with differing interests and values are involved. Uncertainty, for instance about the longer-term consequences of decisions, further increases complexity.

Decision analysis supports systematic thinking to structure the decision problem and to better understand the preferences and values of those involved. It aims at integrating all available information: scientific data and ‘hard facts’ together with the subjective preferences of stakeholders. It improves the process of decision making by increasing its transparency. It aims at making an optimal decision that is well accepted by all parties.

Good decision processes based on Multi-Criteria Decision Analysis (MCDA)

Predictions

Multi-Criteria Decision Analysis (MCDA) allows to analyze the ‘hard facts’, i.e. the predictions about the consequences of choosing a specific decision option. As an example, if engineers have to choose between different wastewater treatment technologies, it is important to know how well nutrients or micropollutants are removed, and how much each option costs. To make sound predictions about the outcome of decision options, modeling techniques or expert assessments can be used.

Uncertainty

Predictions should include uncertainty, such as a lack of scientific knowledge. For instance, one might not exactly know how an ecosystem will react to a management intervention. Predictions are also uncertain due to simplifications in the used models, or because expert judgments are uncertain. Uncertainty increases over long time ranges because the future is not known. In such cases, it can be helpful to integrate scenario planning with MCDA, which allows to consider different possible futures.

Problem structuring

MCDA also analyzes ‘soft data’, namely the preferences of decision makers and stakeholders. A good decision process ensures that the important stakeholders and the people affected by the decision are involved. It can be useful to select participants with stakeholder analysis, which belongs to the large family of Problem Structuring Methods (PSM). Such methods can also help to ensure that there is a proper understanding of the decision situation before using MCDA and that the main objectives of all people involved are considered, possibly including presumed interests of future generations.

Preferences

People have different value systems and therefore different preferences in a decision. This especially affects how people perceive the importance of objectives and how they decide under uncertainty. If not all objectives can be achieved, trade-offs between these conflicting goals have to be made. Preference elicitation techniques help to determine, for instance, how important the achievement of an objective is, and how strongly it can be traded-off with another objective. For example, improving the ecological value of a river to foster an endangered bird species may mean that people can no longer use the river bank for picknicks. Such trade-offs are based on the best and worst possible outcomes of each objective for the specific decision problem (e.g. the costs of the cheapest and most expensive option, or the most user-unfriendly/ -friendly technology). Preference elicition processes (interviews or group workshops) are demanding, because people tend to run into systematic biases when answering our questions. People may also be uncertain about their answers, and they may be risk-averse if the outcomes of the decision (i.e. the predictions) are uncertain.

MCDA modeling and results

Preference elicitation techniques capture the decision maker’s preferences as numbers. These preference parameters enter the decision analysis model together with the ‘hard facts’, the predictions. The result of the MCDA model is a ranking of the decision options from best to worst. If several stakeholders were interviewed, a different ranking may result for each stakeholder. Also, some decision options may be more uncertain than others. The MCDA process helps to select good compromise options that perform reasonably well for all stakeholders despite uncertainty. MCDA should be seen as an iterative process, and it is often useful to refine or construct new decision options based on the insights of the process. It is also very beneficial to discuss the results with stakeholders.

Research topics and methods

A strong research focus of the cluster Decision Analysis is how to better deal with the high complexity in real environmental decisions without making unjustified compromises regarding scientific rigor. Much research in Multi-Criteria Decision Analysis (MCDA) has focused on well defined decision problems. In the real world, decisions tend to be complex and ill defined, with many stakeholders involved and a range of uncertainties to consider.

Our research aims at improving the practicability and reliability of the entire decision making process. This includes all steps of MCDA (see: ‘What is MCDA?’). MCDA is an umbrella term for a number of methods; we focus on Multi-Attribute Value Theory (MAVT) and Multi-Attribute Utility Theory (MAUT).

We develop our research in applied real world projects. Decision makers and stakeholders are strongly involved in the different steps of the decision process. Our transdisciplinary approach is also useful for our case study partners: they gain more insight into their difficult decision problem thanks to our research.

Research topics and some research questions

Problem structuring (framing)

Structuring of the decision problem will strongly affect the outcome of the MCDA. Aim is to include all relevant aspects and important stakeholders and to set up the decision process in such a way that it is best suited to tackle the respective environmental problem. Some research questions are:

  • How to best combine MCDA with Problem Structuring Methods (PSM; e.g. stakeholder analysis, scenario planning, cognitive mapping, strategy generation table, SWOT analysis, Soft Systems Methodology)?
  • Systematization and guidance for best practices in setting up the decision problem.
  • What are good ways to structure objectives hierarchies; what are the pro’s and con’s of reducing complexity?
  • What are good attributes (‘indicators’) that measure the consequences of options in a scientifically precise way, but are at the same time understandable for stakeholders?
Uncertainty

There are various sources of uncertainty. Uncertainty of (i) boundary conditions, e.g. future socio-economic development, (ii) correct framing of decision problems (see above), (iii) the (scientific/ expert) predictions, (iv) decision maker’s preferences, and (v) preferences for decisions under risk.

  • How to best include future scenarios in MCDA-preference elicitation and modeling? How to elicit the decision maker’s preferences if there are different possible futures?
  • How can we make decisions over time if future developments are highly uncertain?
  • When should we focus research efforts on the uncertainty of predictions in a specific decision? How strongly is the decision outcome affected by changed assumptions (sensitivity analyses)?
  • How can we use expert assessments to make predictions if outcomes of an objective are difficult to model and/ or highly uncertain and/ or difficult to understand?
  • How can we elicit utility functions in a practicable and understable way from stakeholders for decisions under risk (MAUT)?
Preference elicitation

A main aim of the cluster Decision Analysis is to find better applicable, simplified elicitation procedures that can readily be applied in complex environmental decision problems. Simplified elicitation will help to transfer research insights into practice and increase real world application of MCDA. However, it is well known from psychological research that humans readily run into biases, violating the axiomatic foundations of MAVT/ MAUT. Preferences can also change for various reasons, and over time.

Internationally, Behavioral Operations Research (BOR) has emerged as an important topic. With our research we wish to contribute to this field. We thus aim at developing elicitation procedures that avoid biases or support de-biasing, that are easily applicable and understandable, and that are reliable and trustworthy. Typical research questions are:

  • What are best methods to elicit marginal value functions and weights (or scaling constants)? How can we aid decision makers during elicitation (e.g. visual and verbal cues, indirect or direct elicitation)?
  • Which aggregation schemes better represent peoples’ preferences if the additive model is inappropriate? How can we elicit the model parameters?
  • Can we effectively reduce interaction with stakeholders by increasing modeling efforts at the beginning of the MCDA?
  • How can we deal with uncertainty (see above): elicit risk attitudes, elicit preferences given different future scenarios, and deal with the decision makers’ uncertainty about their own preferences?
  • How stable are preferences over time? What does this imply for real decision making?
  • How does face-to-face elictation compare to faster elicitation processes (e.g. population surveys, group decision making)?

Methods

Data collection
  • Literature surveys
  • Expert assessment
  • Application and development of models for predictions
  • Problem structuring: workshops
  • Preference elicitation: face-to-face interviews, group workshops, (online) surveys, experiments

  • Evaluation of the process, e.g. questionnaires

Daten analysis
  • Multi-criteria decision analysis (MCDA), specifically Multi-Attribute Value Theory (MAVT) and Multi-Attribute Utility Theory (MAUT); focus on flexibility (e.g. different aggregation models) and uncertainty (e.g. global sensitivity analyses)
  • Problem Structuring Methods (PSM), e.g. stakeholder analysis, scenario planning, cognitive mapping, strategy generation table, SWOT analysis, Soft Systems Methodology
  • Predictions: expert knowledge, modeling, and combinations (Bayesian networks)
  • Literature reviews
  • Statistical analyses (e.g. regression models)
Inter- and transdisciplinary research

The cluster Decision Analysis interacts closely with scientists from other disciplines at Eawag (engineers, chemists, ecotoxicologists, ecologists, and other social scientists from ESS), and with stakeholders in the applied projects.

Introduction to MCDA. Interview with Judit Lienert

Eawag News Article, April 2019

Current Projects

We investigate stakeholders’ preferences, risk attitude, influence, and collaborations for finding consensus options in Swiss governance of plant protection products.

Decision Analysis in plant protection product governance
How to deal with uncertainty in environmental problems, with the aim of improving the communication of uncertainty for better informed decision-making.

Uncertainty and risk communication
We evaluate blue-green infrastructure combinations under future climate conditions and based on the preferences of multiple stakeholders.

Decision Analyis for blue-green infrastructure evaluation

Decision Analysis Tools

Tools to support the steps of Multi-Criteria Decision Analysis (MCDA)

Decision Analysis Tools

Completed Projects

We study how game implementation can support stakeholder involvement and preference modelling in MCDA.

Serious Games as an element of Multi-Criteria Decision Analysis
Serious games and gamification are increasingly used to engage stakeholders. We study whether and how they make decision analysis more participatory.

Environmental Decision Analysis with Games - Edanaga
We aim at improving the use of MCDA in complex environmental problems.

Improving problem structuring in Multi-Criteria Decision Analysis
Goal is an improved planning procedure for sustainable water supply and wastewater infrastructure management that links into the existing Swiss governance structures.

Sustainable Water Infrastructure Planning (SWIP)
MCDA allows integrating ecological assessments with the prediction of consequences of river rehabilitation, and the preferences of experts about trade-offs

A decision analysis approach to river rehabilitation
Removal of pharmaceuticals from hospital wastewater is well accepted by stakeholders if trade-off between good performance of an option and its costs is reasonable.

How to handle hospital wastewater
The population has a high willingness to pay for reducing risks of wastewater flooding or combined sewer overflows

Valuing Adaptation to Climate Change Risks in the Water Sector
We aim at facilitating the use of Multi-Criteria Decision Analysis in urban water management practice.

Value-focused wastewater infrastructure planning
We study well-known fairness principles in the context of wastewater management.

Fairness in the planning of new wastewater infrastructures
Project aim is participative decision support for the long-term transition to innovative wastewater infrastructures.

Decision-making for wastewater infrastructure transitions
Partnership building in information and communication technology (ICT) to provide operational flood forecasting and alerts in West Africa.

FANFAR: Cooperation for flood forecasts and alerts in West Africa
We develop evaluation approaches for planning support systems to improve strategic planning of nature-based solutions in our cities.

MOVE-NBS: Strategic planning of Blue-Green infrastructure

Team

PD Dr. Judit Lienert Group Leader, Group: DA Tel. +41 58 765 5574 Send Mail
Milena Wiget PhD Student, Group: DA Tel. +41 58 765 6749 Send Mail
Anna Cajochen PhD Student, Group: DA Tel. +41 58 765 5621 Send Mail
Dr. Sebastian Schär Postdoc, Group: DA Tel. +41 58 765 5784 Send Mail

Publications

Please note: many of the publications could belong to another category. We assigned them to that category, in which it likely provides the most insight.

Problem structuring: objectives, options, scenarios, stakeholder analysis

Gamifying and evaluating problem structuring: a card game workshop for generating decision objectives

Serious games, gamification, or game-based interventions are increasingly used as tools to aid participatory decision-making processes, but their evaluation is often not very rigorous. Therefore, it is still unclear whether game-based interventions are really beneficial. We focused on the following overarching question: how effective are game-based interventions specifically designed to support decision-making processes. We used an illustrative case to reflect on this question. Using a published framework proposing that design processes of game-based interventions and their evaluation are intertwined, we designed simultaneously (1) a game-based intervention, specifically a card game and a workshop structure in which this card game is to be used, and (2) its evaluation procedure, formulating evaluation questions and proposing measure instruments based on the literature. We pre-tested the evaluation procedure in a small pilot study with 10 students. We illustrate the use of the design framework for an intervention to generate objectives in a decision-making process about sustainable wastewater management. Through our illustrative case, we identify future research opportunities about designing game-based interventions and evaluating their effectiveness. We found that it is possible to address the dual challenge of game-based interventions for participatory decision-making processes: (1) designing an informative and engaging game-based intervention without telling participants what to think and (2) designing a tailored evaluation procedure. Designing the game-based intervention and its evaluation simultaneously is valuable, because both are strongly intertwined. However, conducting the evaluation is demanding and requires the collaborative efforts of scientists, including across disciplinary boundaries. For instance, the data collection effort could be distributed among different research groups to increase sample size. This would allow including control treatment(s) and covering the variation span of the confounding factors more broadly. All material is made openly available to foster collaborative future research.
Aubert, A. H.; McConville, J.; Schmid, S.; Lienert, J. (2022) Gamifying and evaluating problem structuring: a card game workshop for generating decision objectives, EURO Journal on Decision Processes, 10, 100021 (13 pp.), doi:10.1016/j.ejdp.2022.100021, Institutional Repository

Enhancing the elicitation of diverse decision objectives for public planning

Identifying objectives is essential for decision making, but individuals have difficulties stating their important objectives. In public and environmental decisions, the diverse views of stakeholders should be included, but eliciting a broad set of objectives is challenging. We (1) study the effectiveness of individual brainstorming for eliciting objectives in a real-world setting; (2) test three interventions to support individuals in generating objectives; (3) investigate which and how many stakeholders are necessary to generate a comprehensive set of objectives; and (4) develop a feasible elicitation procedure for practice. In an experimental test, 71 stakeholders participated in five decisions about regional wastewater infrastructure planning in Switzerland. Three interventions were tested with an online survey procedure: (i) providing category cues, (ii) a perspective-taking task, and (iii) providing a predefined master list of objectives. In simple brainstorming, participants stated few objectives (M = 3.3) associated with 2.9 different categories on average. Participants consistently missed objectives they later considered important. Providing a master list was the only intervention that substantially increased the number and breadth of objectives (M = 12 objectives in M = 5.3 categories). With the help of our survey, participants generated between 30 and 38 distinct objectives for each decision case. Between five and nine participants were sufficient to generate these; more participants did not contribute new objectives. Most decision makers need help generating their objectives; combining simple brainstorming with a master list is a straightforward improvement that does not require a facilitator. An online process is promising for involving a large group of stakeholders.
Haag, F.; Zürcher, S.; Lienert, J. (2019) Enhancing the elicitation of diverse decision objectives for public planning, European Journal of Operational Research, 279(3), 912-928, doi:10.1016/j.ejor.2019.06.002, Institutional Repository

Methods to inform the development of concise objectives hierarchies in multi-criteria decision analysis

Building a well-structured objectives hierarchy is central to multi-criteria decision analysis (MCDA). However, in the absence of a systematic methodology to support the process, this task has been described as "more art than science". Objectives hierarchies often tend to become large and constraining the size of a hierarchy can be challenging. This paper proposes and illustrates the use of a set of methods to support the simplification of the hierarchies in contexts that are "data rich" and characterised by many objectives. The aim of using the proposed approach is to support decision analysts in developing an appropriately concise decision model for the further interactions with the stakeholders. Using data from two completed environmental cases we show retrospectively how qualitative (means-ends networks), semi-quantitative (relevancy analysis) and quantitative (correlation analysis, principal component analysis, local sensitivity analysis of weights) methods, used alone or in combination, can inform hierarchy development. We evaluate the potential benefits and challenges of each method and discuss the advantages and disadvantages of the simplification of an objectives hierarchy. Questionnaire-based relevancy analysis can be a useful method to identify and communicate important objectives in the early phases of an MCDA process with stakeholders, while correlation analysis can help to identify overlapping objectives, particularly in cases having many objectives and alternatives. It is intended that the methods support a facilitator in developing a clear understanding of the problem and also prompt deeper thinking about and discussion of the appropriate structure and content of an objectives hierarchy with the stakeholders involved.
Marttunen, M.; Haag, F.; Belton, V.; Mustajoki, J.; Lienert, J. (2019) Methods to inform the development of concise objectives hierarchies in multi-criteria decision analysis, European Journal of Operational Research, 277(2), 604-620, doi:10.1016/j.ejor.2019.02.039, Institutional Repository

Identifying relevant objectives in environmental management decisions: an application to a national monitoring program for river restoration

Environmental monitoring covers many different management domains. They range from biodiversity conservation to water protection, natural hazard prevention, impact assessment, resource use, or environmental restoration. The need for clear objectives has long been emphasized in the management literature, but has often received only little attention in monitoring design. This is partly due to the lack of systematic approaches for setting objectives. In this paper, we present a formal approach based on Multi-Criteria Decision Analysis (MCDA), namely relevancy analysis, to prioritize management objectives. We demonstrate its use for a river restoration monitoring program in Switzerland comprising 35 physical and biological objectives. The relevancy of an objective is based on two main components, the general importance of the objective, and the problemspecific impact range. The general importance of an objective is used to identify the most important management objectives from a hierarchy within the national program (i.e. objectives to be monitored). The impact range is used to understand which management objectives are more important to monitor for different river restoration measures (i.e. sub-selection of the objectives specifically for the restoration measure). The general importance of a management objective was determined based on the frequency an objective is mentioned in selected policy documents, and the legislative power and temporal persistency of each document. The impact ranges were identified from a questionnaire involving 15 Swiss river restoration professionals. Hereby, we assumed that the impact range increases as the anticipated impact of the restoration measure on a specific management objective increases, and as the uncertainty to anticipate this impact increases. For simplicity, we applied the approach only to one restoration measure, namely river widening. Six management objectives scored high in relevancy in terms of both impact range and general importance – channel structure and diversity, structure and diversity of the banks and floodplains, sediment dynamics, longitudinal connectivity, lateral connectivity, and vertical connectivity. Hence, these objectives are both important national objectives for river monitoring (according to the legislation) and are objectives that are potentially highly impacted by a river widening project. We performed sensitivity analyses related to the calculation of the general importance, the impact range, and the relevancy of the objectives. The practice-oriented approach can be transferred to a broad diversity of decision situations where there is a need for systematic evaluation of the importance of objectives. It could be a useful tool for social learning and finding group consensus about the priority of the objectives.
Marttunen, M.; Weber, C.; Åberg, U.; Lienert, J. (2019) Identifying relevant objectives in environmental management decisions: an application to a national monitoring program for river restoration, Ecological Indicators, 101, 851-866, doi:10.1016/j.ecolind.2018.11.042, Institutional Repository

Towards a new paradigm of urban water infrastructure: identifying goals and strategies to support multi-benefit municipal wastewater treatment

Over the past decade, water professionals have begun to focus on a new paradigm for urban water systems, which entails the recovery of resources from wastewater, the integration of engineered and natural systems, and coordination among agencies managing different facets of water systems. In the San Francisco Bay Area, planning for nutrient management serves as an exemplary model of this transition. We employed a variety of methodological approaches including stakeholder analysis, multi-criteria decision-making weight elicitation, and document analysis to understand and support decision-making in this context. Based on interviews with 32 stakeholders, we delineate goals that are considered to be important for achieving the new paradigm and we highlight management strategies that can help reach these goals. We identify and analyze the social, institutional, and technical impediments to planning and implementing multi-benefit wastewater infrastructure projects and identify strategies to overcome some of these challenges. Transitioning to a new paradigm for urban water infrastructure will require stakeholders to proactively forge collaborative relationships, jointly define a shared vision and objectives, and build new rules to overcome limitations of current institutional policies.
Harris-Lovett, S.; Lienert, J.; Sedlak, D. L. (2018) Towards a new paradigm of urban water infrastructure: identifying goals and strategies to support multi-benefit municipal wastewater treatment, Water, 10(9), 1127 (22 pp.), doi:10.3390/w10091127, Institutional Repository

Are objectives hierarchy related biases observed in practice? A meta-analysis of environmental and energy applications of Multi-Criteria Decision Analysis

Procedural and behavioural biases have received little attention in recent Multi-Criteria Decision Analysis (MCDA) research. Our literature review shows that most research on biases was done 15–30 years ago. This study focuses on biases that are introduced at an early stage of MCDA when building objectives hierarchies and their effect on the weights. The main objective is to investigate whether prior findings regarding such biases, which were mostly based on laboratory experiments, can be found in real-world applications. We conducted a meta-analysis of the objectives hierarchies and weight elicitation procedures in 61 environmental and energy MCDA cases. Relationships between the structural characteristics of the objectives hierarchy and assigned objectives’ weights were analysed with statistical tests. Our main research questions were: (i) How does hierarchy size and structure affect the objectives’ weights? (ii) How are weights distributed across economic, social and environmental objectives? (iii) Is there support for the equalising bias? Our findings are mostly aligned with earlier research and suggest that the hierarchy structure and content can substantially influence weight distributions. For example, hierarchical weighting seems to be sensitive to the asymmetry bias, which can occur when a hierarchy has branches that differ in the number of sub-objectives. We found no evidence for the equalising bias. We highlight issues deserving more attention when developing objectives hierarchies and eliciting weights. The research demonstrates the potential to use meta-analysis, which has not previously been used in this way in the MCDA field, to learn from a collection of applications.
Marttunen, M.; Belton, V.; Lienert, J. (2018) Are objectives hierarchy related biases observed in practice? A meta-analysis of environmental and energy applications of Multi-Criteria Decision Analysis, European Journal of Operational Research, 265(1), 178-194, doi:10.1016/j.ejor.2017.02.038, Institutional Repository

Structuring problems for multi-criteria decision analysis in practice: a literature review of method combinations

Structuring problems for Multi-Criteria Decision Analysis (MCDA) has attracted increasing attention over the past 20 years from both a conceptual and a practical perspective. This is reflected in a significant growth in the number of published applications which use a formal approach to problem structuring in combination with an analytic method for multi-criteria analysis. The problem structuring approaches (PSMs) include general methodologies such as Checkland's Soft Systems Method (SSM), Eden and Ackermann's Strategic Options Design and Analysis (SODA) and other methods that focus on a particular aspect. We carried out a literature review that covers eight PSMs (Cognitive and Causal Maps, DPSIR, Scenario Planning, SSM, Stakeholder Analysis, Strategic Choice Approach, SODA and SWOT) and seven MCDA methods (AHP, ANP, ELECTRE, MAUT, MAVT, PROMETHEE and TOPSIS). We first identified and analysed 333 articles published during 2000-2015, then selected 68 articles covering all PSM-MCDA combinations, which were studied in detail to understand the associated processes, benefits and challenges. The three PSMs most commonly combined with MCDA are SWOT, Scenario Planning and DPSIR. AHP was by far the most commonly applied MCDA method. Combining PSMs with MCDA produces a richer view of the decision situation and enables more effective support for different phases of the decision-making process. Some limitations and challenges in combining PSMs and MCDA are also identified, most importantly relating to building a value tree and assigning criteria weights.
Marttunen, M.; Lienert, J.; Belton, V. (2017) Structuring problems for multi-criteria decision analysis in practice: a literature review of method combinations, European Journal of Operational Research, 263(1), 1-17, doi:10.1016/j.ejor.2017.04.041, Institutional Repository

Structured decision-making for sustainable water infrastructure planning and four future scenarios

Water supply and wastewater infrastructures are vital for human well-being and environmental protection; they adhere to the highest standards, are expensive and long-lived. Because they are also aging, substantial planning is required. Climate and socio-economic change create large planning uncertainties and simple projections of past developments are no longer adequate. This paper presents the initial phases of a structured decision-making (SDM) procedure which is designed to increase the sustainability of water infrastructure planning and includes various stakeholders in an exemplary Swiss case study. We evaluate the SDM approach critically based on stakeholder feedback, give general recommendations and provide ample material to make it applicable to other settings. We carried out 27 interviews and two stakeholder workshops. We identified important objectives for water infrastructure planning, including all three sustainability pillars and their respective attributes (indicators, benchmarks) to measure how well the objectives are achieved. We then created strategic decision alternatives, including "business-as-usual" upgrades of the central water supply and wastewater system as well as semi- to fully decentralized alternatives. To tackle future uncertainty, we developed four socio-demographic scenarios. We used these to test the robustness of decision alternatives in a later Multi-Attribute Utility Theory analysis. Additionally, we contribute to the topical discussion of combining scenario planning with multi-criteria decision analysis and demonstrate how various scenarios can stimulate creativity when generating decision alternatives. Their internal consistency is ensured by rigorously specifying them using a strategy generation table. Our SDM procedure can be adapted to inform decisions about sustainable water infrastructures in other contexts.
Lienert, J.; Scholten, L.; Egger, C.; Maurer, M. (2015) Structured decision-making for sustainable water infrastructure planning and four future scenarios, EURO Journal on Decision Processes, 3, 107-140, doi:10.1007/s40070-014-0030-0, Institutional Repository

Additional information for "Structured decision-making for sustainable water infrastructure planning and four future scenarios"

To support Sustainable Water Infrastructure Planning (SWIP), a participatory decision-making procedure was developed in the SWIP project at Eawag1. This procedure is based on Structured Decision Making (SDM)2, which guides stakeholders through different steps of the decision process: (1) clarify decision context (may include a stakeholder analysis); (2) define objectives and attributes; (3) develop alternatives; (4) estimate consequences; (5) evaluate trade-offs and select alternatives; and (6) implement, monitor and review.
The SDM application to water infrastructure planning was developed in close collaboration with stakeholders in a case study near Zürich, Switzerland. The experienced advantages and disadvantages of the first steps of the proposed procedure were discussed in a scientific publication by Lienert et al. (2014)3. We strongly encourage others to apply this SDM procedure for sustainable water infrastructure planning to their specific case. To this end, the approach was developed in a generalized way and we present more material covering the different steps of the SDM procedure in this working paper.
The here presented material includes different steps in the development of a comprehensive objectives hierarchy for water supply and wastewater management. The objectives are operationalized with attributes (indicators/ benchmarks), which are described in detail, including the ranges (best- and worst-possible case) and a description of the status quo. Four future scenarios were developed in a scenario planning workshop together with local stakeholders to capture socio-demographic uncertainty, which are again described in detail. Ten strategic decision alternatives were developed by stakeholders with help of a strategy generation table. These include the current system with central water supply and wastewater treatment plants, but also fully decentralized on-site options and different management strategies. The strategy generation table can be used to tailor decision alternatives for water infrastructure planning to other cases. Finally, we provide detailed feedback from the stakeholders for each step. We evaluate the proposed SDM approach and give recommendations for other applications.
Lienert, J.; Scholten, L.; Egger, C.; Maurer, M. (2015) Additional information for "Structured decision-making for sustainable water infrastructure planning and four future scenarios", 48 p, Institutional Repository

Stakeholder analysis combined with social network analysis provides fine-grained insights into water infrastructure planning processes

Environmental policy and decision-making are characterized by complex interactions between different actors and sectors. As a rule, a stakeholder analysis is performed to understand those involved, but it has been criticized for lacking quality and consistency. This lack is remedied here by a formal social network analysis that investigates collaborative and multi-level governance settings in a rigorous way. We examine the added value of combining both elements. Our case study examines infrastructure planning in the Swiss water sector. Water supply and wastewater infrastructures are planned far into the future, usually on the basis of projections of past boundary conditions. They affect many actors, including the population, and are expensive. In view of increasing future dynamics and climate change, a more participatory and long-term planning approach is required. Our specific aims are to investigate fragmentation in water infrastructure planning, to understand how actors from different decision levels and sectors are represented, and which interests they follow. We conducted 27 semi-structured interviews with local stakeholders, but also cantonal and national actors. The network analysis confirmed our hypothesis of strong fragmentation: we found little collaboration between the water supply and wastewater sector (confirming horizontal fragmentation), and few ties between local, cantonal, and national actors (confirming vertical fragmentation). Infrastructure planning is clearly dominated by engineers and local authorities. Little importance is placed on longer-term strategic objectives and integrated catchment planning, but this was perceived as more important in a second analysis going beyond typical questions of stakeholder analysis. We conclude that linking a stakeholder analysis, comprising rarely asked questions, with a rigorous social network analysis is very fruitful and generates complementary results. This combination gave us deeper insight into the socio-political-engineering world of water infrastructure planning that is of vital importance to our well-being.
Lienert, J.; Schnetzer, F.; Ingold, K. (2013) Stakeholder analysis combined with social network analysis provides fine-grained insights into water infrastructure planning processes, Journal of Environmental Management, 125, 134-148, doi:10.1016/j.jenvman.2013.03.052, Institutional Repository

Impact and performance assessment

Comparing multi-criteria decision analysis and integrated assessment to support long-term water supply planning

We compare the use of multi-criteria decision analysis (MCDA)–or more precisely, models used in multi-attribute value theory (MAVT)–to integrated assessment (IA) models for supporting long-term water supply planning in a small town case study in Switzerland. They are used to evaluate thirteen system scale water supply alternatives in four future scenarios regarding forty-four objectives, covering technical, social, environmental, and economic aspects. The alternatives encompass both conventional and unconventional solutions and differ regarding technical, spatial and organizational characteristics. This paper focuses on the impact assessment and final evaluation step of the structured MCDA decision support process. We analyze the performance of the alternatives for ten stakeholders. We demonstrate the implications of model assumptions by comparing two IA and three MAVT evaluation model layouts of different complexity. For this comparison, we focus on the validity (ranking stability), desirability (value), and distinguishability (value range) of the alternatives given the five model layouts. These layouts exclude or include stakeholder preferences and uncertainties. Even though all five led us to identify the same best alternatives, they did not produce identical rankings. We found that the MAVT-type models provide higher distinguishability and a more robust basis for discussion than the IA-type models. The needed complexity of the model, however, should be determined based on the intended use of the model within the decision support process. The best-performing alternatives had consistently strong performance for all stakeholders and future scenarios, whereas the current water supply system was outperformed in all evaluation layouts. The best-performing alternatives comprise proactive pipe rehabilitation, adapted firefighting provisions, and decentralized water storage and/or treatment. We present recommendations for possible ways of improving water supply planning in the case study and beyond.
Scholten, L.; Maurer, M.; Lienert, J. (2017) Comparing multi-criteria decision analysis and integrated assessment to support long-term water supply planning, PLoS One, 12(5), e0176663 (30 pp.), doi:10.1371/journal.pone.0176663, Institutional Repository

Combining expert knowledge and local data for improved service life modeling of water supply networks

The presented approach aims to overcome the scarce data problem in service life modeling of water networks by combining subjective expert knowledge and local replacement data. A procedure to elicit imprecise quantile estimates of survival functions from experts, considering common cognitive biases, was developed and applied. The individual expert priors of the parameters of the service life distribution are obtained by regression over the stated distribution quantiles and aggregated into a single prior distribution. Furthermore, a likelihood function for the commonly encountered censored and truncated pipe replacement data is formulated. The suitability of the suggested Bayesian approach based on elicitation data from eight experts and real network data is demonstrated. Robust parameter estimates could be derived in data situations where frequentist maximum likelihood estimation is unsatisfactory, and to show how the consideration of imprecision and in-between-variance of experts improves posterior inference.
Scholten, L.; Scheidegger, A.; Reichert, P.; Maurer, M. (2013) Combining expert knowledge and local data for improved service life modeling of water supply networks, Environmental Modelling and Software, 42, 1-16, doi:10.1016/j.envsoft.2012.11.013, Institutional Repository

Environmental toxicology and risk assessment of pharmaceuticals from hospital wastewater

In this paper, we evaluated the ecotoxicological potential of the 100 pharmaceuticals expected to occur in highest quantities in the wastewater of a general hospital and a psychiatric center in Switzerland. We related the toxicity data to predicted concentrations in different wastewater streams to assess the overall risk potential for different scenarios, including conventional biological pretreatment in the hospital and urine source separation. The concentrations in wastewater were estimated with pharmaceutical usage information provided by the hospitals and literature data on human excretion into feces and urine. Environmental concentrations in the effluents of the exposure scenarios were predicted by estimating dilution in sewers and with literature data on elimination during wastewater treatment. Effect assessment was performed using quantitative structure-activity relationships because experimental ecotoxicity data were only available for less than 20% of the 100 pharmaceuticals with expected highest loads. As many pharmaceuticals are acids or bases, a correction for the speciation was implemented in the toxicity prediction model.
The lists of Top-100 pharmaceuticals were distinctly different between the two hospital types with only 37 pharmaceuticals overlapping in both datasets. 31 Pharmaceuticals in the general hospital and 42 pharmaceuticals in the psychiatric center had a risk quotient above 0.01 and thus contributed to the mixture risk quotient. However, together they constituted only 14% (hospital) and 30% (psychiatry) of the load of pharmaceuticals. Hence, medical consumption data alone are insufficient predictors of environmental risk. The risk quotients were dominated by amiodarone, ritonavir, clotrimazole, and diclofenac. Only diclofenac is well researched in ecotoxicology, while amiodarone, ritonavir, and clotrimazole have no or very limited experimental fate or toxicity data available. The presented computational analysis thus helps setting priorities for further testing.
Separate treatment of hospital wastewater would reduce the pharmaceutical load of wastewater treatment plants, and the risk from the newly identified priority pharmaceuticals. However, because high-risk pharmaceuticals are excreted mainly with feces, urine source separation is not a viable option for reducing the risk potential from hospital wastewater, while a sorption step could be beneficial.
Escher, B. I.; Baumgartner, R.; Koller, M.; Treyer, K.; Lienert, J.; McArdell, C. S. (2011) Environmental toxicology and risk assessment of pharmaceuticals from hospital wastewater, Water Research, 45(1), 75-92, doi:10.1016/j.watres.2010.08.019, Institutional Repository

Preference elicitation and preference modeling

Can online interfaces enhance learning for public decision-making? Eliciting citizens' preferences for multicriteria decision analysis

Innovative online interfaces informing and consulting citizens about their preferences for multicriteria decision analysis (MCDA) could make public decision-making more participatory. We propose a three-faceted learning for decision-making framework and used it to test newly-designed online weight elicitation interfaces. We investigated two features meant to enhance learning: fully-fledged gamification with a narrative, interaction with nonplayer characters, and ambient music, and learning loops (LL) using consistency checks of elicited weights and the challenge to resolve inconsistencies. We operationalized our framework with a novel systematic set of measure instruments providing complementary data types. We designed a 2 × 2 between-subject experiment with pre- and postquestionnaires. Answers from 769 respondents, representative of the Swiss population in age and gender, indicated that the interfaces successfully raised awareness about wastewater management. Gamification was helpful: respondents performed better in the factual learning test, and unexpected social learning occurred. However, gamification lowered the perception of process understanding. The LL were beneficial: objectively, respondents performed better in the factual learning test. However, respondents perceived the LL as cognitively demanding and their factual learning as lower. Our structured assessment highlighted the need for further research to investigate, for instance, high interpersonal variability and the disparities between tested and perceived learning. Measuring preference construction remains challenging; and social learning should be added to the assessment framework. Applying such structured assessment of learning outcomes to more traditional operational research interventions would provide a baseline for future comparison.
Aubert, A. H.; Schmid, S.; Lienert, J. (2024) Can online interfaces enhance learning for public decision-making? Eliciting citizens' preferences for multicriteria decision analysis, European Journal of Operational Research, 314(2), 760-775, doi:10.1016/j.ejor.2023.10.031, Institutional Repository

Preference change in stakeholder group-decision processes in the public sector: extent, causes and implications

Public decisions are typically related to large investments leaving long legacies. We should therefore strive for wide societal agreement regarding such decisions, which meet the diversity of preferences between stakeholders and over time. But if, how and why do stakeholder preferences change over time? In decision analysis, these questions received little attention. We explored them using three real-world public decision processes, based on Multi-Criteria Decision Analysis (MCDA). We used repeatedly elicited ranking of objectives over time. These were obtained during three to five moderated workshops we organised several months apart (total N = 200 questionnaires, and 100 stakeholders). We analysed individual and aggregated (group) preferences, their changes and potential drivers including demographic and experience variables. We also analysed the effect of preference evolution on the performance of decision-alternatives with MCDA over time. We found that stakeholder preferences often changed over time, both on an individual and group level. These changes did not systematically diminish over time, but some convergence of preferences was observed for stakeholders who repeatedly participated in workshops. High-ranking objectives were relatively stable and similar between stakeholders. While preference changes could not be explained by demographics and personal experiences, repeated interaction with the decision problem might play a role. Neither the observed disagreement between stakeholders, nor the preference changes over time affected the best and worst performing alternatives in our decision problems. Thus, despite changing stakeholder preferences over time, public decision-makers can contrive robust solutions to complex public decision problems in the present.
Kuller, M.; Beutler, P.; Lienert, J. (2023) Preference change in stakeholder group-decision processes in the public sector: extent, causes and implications, European Journal of Operational Research, 308, 1268-1285, doi:10.1016/j.ejor.2022.12.001, Institutional Repository

Gamified environmental multi‐criteria decision analysis: information on objectives and range insensitivity bias

Multi-criteria decision analysis (MCDA) is well suited to address complex public policy problems but could benefit from new tools to involve many laypeople. Online information on specialized topics could be more engaging by including game elements. This paper reports an experiment that assessed a gamified interface to (1) inform laypeople about the objectives to consider in wastewater management decisions, (2) assist them in constructing range-based preferences, and (3) provide a positive experience. We measured the effects with (1) a knowledge pre- and posttest, (2) the elicited weights and a range sensitivity index, and (3) an experience questionnaire based on self-determination theory. Answers from 174 participants indicated that participants learnt about the objectives and constructed preferences in both the gamified and control treatments. However, in neither were weights sufficiently adjusted. Our gamification making the ranges salient did not help overcome this bias. Both treatments were experienced as neutral to positive, the gamified being more entertaining. We discuss implications: if gamification of tools for participatory decision-making is to be promoted, it requires further research. Range insensitivity remains an unresolved bias in MCDA.
Aubert, A. H.; Lienert, J.; von Helversen, B. (2023) Gamified environmental multi‐criteria decision analysis: information on objectives and range insensitivity bias, International Transactions in Operational Research, 30(6), 3738-3770, doi:10.1111/itor.13206, Institutional Repository

Gamified online survey to elicit citizens' preferences and enhance learning for environmental decisions

Multi-Criteria Decision Analysis (MCDA) requires a critical step, namely to elicit individual preferences. On the basis of learning theories, we formalize preference construction as learning about facts and values, and as a process; we also conceptualize an online preference elicitation survey that offers learning loops to increase factual learning and support preference construction. Another originality is gamification. Game elements (a narrative and non-player characters as motivational affordance) keep respondents engaged in the demanding task of weight elicitation. Our tool enables broad public participation in MCDA, allowing reliable online preference elicitation. The survey concept was tested with 107 students and a control treatment. Quantitative and qualitative data indicate that the concept works. Participants’ factual knowledge increased. The survey helped students to learn about their own preferences concerning the importance of objectives. The practical implication is that weighting can be reliably elicited by online surveys. Participants reported a positive experience; further ways to improve it are thoroughly discussed.
Aubert, A. H.; Lienert, J. (2019) Gamified online survey to elicit citizens' preferences and enhance learning for environmental decisions, Environmental Modelling and Software, 111, 1-12, doi:10.1016/j.envsoft.2018.09.013, Institutional Repository

Identifying non-additive multi-attribute value functions based on uncertain indifference statements

Multi-criteria decision analysis (MCDA) requires an accurate representation of the preferences of decision-makers, for instance in the form of a multi-attribute value function. Typically, additivity or other stringent assumptions about the preferences are made to facilitate elicitation by assuming a simple parametric form. When relaxing such assumptions, parameters cannot be elicited easily with standard methods. We present a novel approach for identifying multi-attribute value functions which can have any shape. As preference information indifference statements are used that can be elicited by trade-off questions. Instead of asking one indifference statement for each pair of attributes, we ask for multiple trade-offs at different points in the attribute space. This allows inferring parameters of complex value functions despite the simplicity of the preference statements. Parameters are estimated by taking into account preference and elicitation uncertainty with a probabilistic model. Statistical inference supports identifying the most adequate preference model out of several candidate models through quantifying the uncertainty and assessing the need for non-additivity. The approach is elaborated for determining value functions by hierarchical aggregation. We apply it to an assessment of the ecological state of rivers, which is used to support environmental management decisions in Switzerland. Preference models of four experts were quantified, confirming the feasibility of the approach and the relevance of considering non-additive functions. The method suggests a promising direction for improving the representation of preferences.
Haag, F.; Lienert, J.; Schuwirth, N.; Reichert, P. (2019) Identifying non-additive multi-attribute value functions based on uncertain indifference statements, Omega: the international journal of management science, 85, 49-67, doi:10.1016/j.omega.2018.05.011, Institutional Repository

Stakeholder interviews with two MAVT preference elicitation philosophies in a Swiss water infrastructure decision: aggregation using SWING-weighting and disaggregation using UTAGMS

We used two types of preference elicitation methods based on multi-attribute value theory (MAVT) for a wastewater infrastructure decision in Switzerland. We aimed to register the implementation impacts of two preference elicitation philosophies (aggregation, disaggregation) in a large, real-world case and give guidance on these elicitation approaches for practitioners. We conducted two series of face-to-face inter- views with the same ten. The first interview set used direct aggregation preference elicitation methods, which decomposed an additive value model into the elicitation of weights (SMART/SWING-variant) and marginal value functions (bi-section method). In the second interview series, indirect disaggregation was used, based on UTAGMS . The weights and marginal value functions for 19 objectives were later simulta- neously inferred with linear programming from pairwise comparisons of hypothetical alternatives. One aim was to design the UTAGMS comparisons for many objectives. Further, we aimed to identify differ- ences and commonalities of the two methods concerning the elicited preferences, the MAVT evaluation results of six real-world wastewater infrastructure alternatives, and the stakeholders’ and analysts’ feed- backs. Similar best alternatives indicate convergence of the two elicitation methods. This demonstrates the applicability of the UTAGMS elicitation procedure to a very complex decision problem. However, the two elicitation methods were perceived differently by the respondents and required different effort from the analysts. For individual stakeholders, preferences were sometimes rather different between the inter- views, which could be largely explained by the constructive nature of preference formation. This indicates the importance of supporting stakeholder learning in the application of MCDA.
Zheng, J.; Lienert, J. (2018) Stakeholder interviews with two MAVT preference elicitation philosophies in a Swiss water infrastructure decision: aggregation using SWING-weighting and disaggregation using UTAGMS, European Journal of Operational Research, 267(1), 273-287, doi:10.1016/j.ejor.2017.11.018, Institutional Repository

Four common simplifications of multi-criteria decision analysis do not hold for river rehabilitation

River rehabilitation aims at alleviating negative effects of human impacts such as loss of biodiversity and reduction of ecosystem services. Such interventions entail difficult trade-offs between different ecological and often socio-economic objectives. Multi-Criteria Decision Analysis (MCDA) is a very suitable approach that helps assessing the current ecological state and prioritizing river rehabilitation measures in a standardized way, based on stakeholder or expert preferences. Applications of MCDA in river rehabilitation projects are often simplified, i.e. using a limited number of objectives and indicators, assuming linear value functions, aggregating individual indicator assessments additively, and/or assuming risk neutrality of experts. Here, we demonstrate an implementation of MCDA expert preference assessments to river rehabilitation and provide ample material for other applications. To test whether the above simplifications reflect common expert opinion, we carried out very detailed interviews with five river ecologists and a hydraulic engineer. We defined essential objectives and measurable quality indicators (attributes), elicited the experts´ preferences for objectives on a standardized scale (value functions) and their risk attitude, and identified suitable aggregation methods. The experts recommended an extensive objectives hierarchy including between 54 and 93 essential objectives and between 37 to 61 essential attributes. For 81% of these, they defined non-linear value functions and in 76% recommended multiplicative aggregation. The experts were risk averse or risk prone (but never risk neutral), depending on the current ecological state of the river, and the experts´ personal importance of objectives. We conclude that the four commonly applied simplifications clearly do not reflect the opinion of river rehabilitation experts. The optimal level of model complexity, however, remains highly case-study specific depending on data and resource availability, the context, and the complexity of the decision problem.
Langhans, S. D.; Lienert, J. (2016) Four common simplifications of multi-criteria decision analysis do not hold for river rehabilitation, PLoS One, 11(3), e0150695 (27 pp.), doi:10.1371/journal.pone.0150695, Institutional Repository

Preference stability over time with multiple elicitation methods to support wastewater infrastructure decision-making

We used a multi-method and repeated elicitation approach across different stakeholder groups to explore possible differences in the outcome of an environmental decision. We compared different preference elicitation procedures based on Multi Criteria Decision Analysis (MCDA) over time for a water infrastructure decision in Switzerland. We implemented the SWING and SMART/SWING weight elicitation methods and also compared results with earlier stakeholder interviews. In all procedures, the weights for environmental protection and well-functioning (waste-)water systems were higher than for cost reduction. The SMART/SWING variant produced statistically significantly different weights than SWING. Weights changed over time with both elicitation methods. Weights were more stable with the SWING method, which was also perceived as slightly more difficult than the SMART/SWING variant. We checked whether the difference in weights produced by the two elicitation methods and the difference in their stability affects the ranking of six alternatives. Overall an unconventional decentralized alternative ranked first or second in 92 percent of all elicitation procedures, which were the online surveys or interviews. For practical decision-making, using multiple methods across different stakeholder groups and repeating elicitation can increase our confidence that the results reflect the true opinions of the decision makers and stakeholders.
Lienert, J.; Duygan, M.; Zheng, J. (2016) Preference stability over time with multiple elicitation methods to support wastewater infrastructure decision-making, European Journal of Operational Research, 253(3), 746-760, doi:10.1016/j.ejor.2016.03.010, Institutional Repository

Multi-criteria decision analysis: concepts, methods, uncertainty

Operational research for, with, and by citizens: an overview

Interest in citizen participation is increasing generally. Almost all operational research (OR) is engaged with clients, but it is mainly in the areas of Soft and Community OR that wider stakeholder and citizen participation has been a significant focus. It is the involvement of citizens that is the subject of this paper. We surveyed OR literature and compiled a corpus of 62 studies, the earliest from 1970, to systematically characterize the involvement of citizens in OR processes. Our review produced three findings: First, some fields of OR have embraced citizen participation, but this is not yet a major concern outside the field of Community OR. Second, citizen participation in OR processes is often driven by a moral rationale. Third, progress in information and communication technology (ICT) enables broad participation, but traditional processes requiring physical presence can also be participatory. From these insights, we formulate research opportunities for OR. (1) OR may join Community OR's endeavor to engage with and empower citizens who have so far rarely been involved in OR processes. (2) OR may identify benefits and drawbacks of digital OR processes in empirical studies. (3) OR may determine whether involving large numbers of citizens is suitable for the societal scale. (4) OR may research building and maintaining trust. (5) OR may join efforts for data protection of participants. (6) OR may systematically report and reflect on participatory OR processes. (7) OR should continue researching the fair aggregation of individual inputs. Citizen participation in OR is topical and challenging. Pursuing these research opportunities will contribute to OR fulfilling its mandate of better decision-making in close cooperation with all affected stakeholders.
Aubert, A. H.; Lienert, J. (2024) Operational research for, with, and by citizens: an overview, European Journal of Operational Research, 316(3), 800-814, doi:10.1016/j.ejor.2023.10.037, Institutional Repository

Lienert, J. (2022) App helps with difficult decisions (App hilft bei schwierigen Entscheiden). Interview by Barbara Vonarburg with Judit Lienert, Eawag News, April 2022.

ValueDecisions, a web app to support decisions with conflicting objectives, multiple stakeholders, and uncertainty

Complex environmental and public policy decisions profit from structured procedures such as multi-criteria decision analysis (MCDA). To support such decisions, the new open source application ValueDecisions provides advanced analysis and visualization with no programming expected from users. Based on multi-attribute value theory (MAVT), it offers analysis for decisions with conflicting and interacting objectives, multiple stakeholders, and uncertain consequences of options. Programmed in R, the shiny web framework makes it accessible via a graphical user interface in the browser. We exemplify using ValueDecisions for a wastewater infrastructure planning case in the Paris region. We surveyed preferences of 655 citizens and conducted sensitivity analysis of preference parameters. The best management options were robust across a range of preference profiles and assumptions. To evaluate the app, we developed a novel usability test based on the ISO standard for software quality and surveyed students using ValueDecisions for case studies.
Haag, F.; Aubert, A. H.; Lienert, J. (2022) ValueDecisions, a web app to support decisions with conflicting objectives, multiple stakeholders, and uncertainty, Environmental Modelling and Software, 150, 105361 (19 pp.), doi:10.1016/j.envsoft.2022.105361, Institutional Repository

Integrating uncertainty of preferences and predictions in decision models: an application to regional wastewater planning

Decision-making in environmental management requires eliciting preferences of stakeholders and predicting outcomes of decision alternatives. Usually, preferences and predictions are both uncertain. Uncertainty of predictions can be tackled by multi-attribute utility theory, but the uncertainty of preferences remains a challenge. We demonstrate an approach for including both uncertainties in a multi-criteria decision analysis (MCDA), using utility theory and the concept of expected expected utility. For a decision regarding a regional merger of wastewater infrastructure in Switzerland, we constructed preference models for four stakeholders. These models also allowed for non-additive interactions between objectives. We evaluated the performance of eleven decision alternatives for which we predicted potential outcomes. Even though uncertainties were high, we could draw conclusions based on the expected expected utility of alternatives. Building a pipeline to discharge treated wastewater to a larger river emerged as a potential consensus alternative to mitigate the problem of micropollutants in a small stream. We investigated the robustness of the findings with sensitivity analysis regarding the preference parameters and the included objectives. In their actual decision, the stakeholders partly preferred other alternatives than those proposed by the model. Their choices could be explained by reduced decision models in which only few objectives were included. This may indicate the use of simplified choice heuristics by the stakeholders. The presented approach is feasible for supporting other difficult environmental or engineering decisions in practice, for which we give a number of recommendations.
Haag, F.; Reichert, P.; Maurer, M.; Lienert, J. (2019) Integrating uncertainty of preferences and predictions in decision models: an application to regional wastewater planning, Journal of Environmental Management, 252, 109652 (16 pp.), doi:10.1016/j.jenvman.2019.109652, Institutional Repository

A review of water-related serious games to specify use in environmental Multi-Criteria Decision Analysis

Serious games and gamification are nowadays pervasive. They are used to communicate about science and sometimes to involve citizens in science (e.g. citizen science). Concurrently, environmental decision analysis is challenged by the high cognitive load of the decision-making process and the possible biases threatening the rationality assumptions. Difficult decision-making processes can result in incomplete preference construction, and are generally limited to few participants. We reviewed 43 serious games and gamified applications related to water. We covered the broad diversity of serious games, which could be explained by the still unsettled terminology in the research area of gamification and serious gaming. We discuss how existing games could benefit early steps of Multi-Criteria Decision Analysis (MCDA), including problem structuring, stakeholder analysis, defining objectives, and exploring alternatives. We argue that no existing game allows for preference elicitation; one of the most challenging steps of MCDA. We propose many research opportunities for behavioral operational research.
Aubert, A. H.; Bauer, R.; Lienert, J. (2018) A review of water-related serious games to specify use in environmental Multi-Criteria Decision Analysis, Environmental Modelling and Software, 105, 64-78, doi:10.1016/j.envsoft.2018.03.023, Institutional Repository

The conceptual foundation of environmental decision support

Environmental decision support intends to use the best available scientific knowledge to help decision makers find and evaluate management alternatives. The goal of this process is to achieve the best fulfillment of societal objectives. This requires a careful analysis of (i) how scientific knowledge can be represented and quantified, (ii) how societal preferences can be described and elicited, and (iii) how these concepts can best be used to support communication with authorities, politicians, and the public in environmental management. The goal of this paper is to discuss key requirements for a conceptual framework to address these issues and to suggest how these can best be met. We argue that a combination of probability theory and scenario planning with multi-attribute utility theory fulfills these requirements, and discuss adaptations and extensions of these theories to improve their application for supporting environmental decision making. With respect to (i) we suggest the use of intersubjective probabilities, if required extended to imprecise probabilities, to describe the current state of scientific knowledge. To address (ii), we emphasize the importance of value functions, in addition to utilities, to support decisions under risk. We discuss the need for testing "non-standard" value aggregation techniques, the usefulness of flexibility of value functions regarding attribute data availability, the elicitation of value functions for sub-objectives from experts, and the consideration of uncertainty in value and utility elicitation. With respect to (iii), we outline a well-structured procedure for transparent environmental decision support that is based on a clear separation of scientific prediction and societal valuation. We illustrate aspects of the suggested methodology by its application to river management in general and with a small, didactical case study on spatial river rehabilitation prioritization.
Reichert, P.; Langhans, S. D.; Lienert, J.; Schuwirth, N. (2015) The conceptual foundation of environmental decision support, Journal of Environmental Management, 154, 316-332, doi:10.1016/j.jenvman.2015.01.053, Institutional Repository

Tackling uncertainty in multi-criteria decision analysis – an application to water supply infrastructure planning

We present a novel approach for practically tackling uncertainty in preference elicitation and predictive modeling to support complex multi-criteria decisions based on multi-attribute utility theory (MAUT). A simplified two-step elicitation procedure consisting of an online survey and face-to-face interviews is followed by an extensive uncertainty analysis. This covers uncertainty of the preference components (marginal value and utility functions, hierarchical aggregation functions, aggregation parameters) and the attribute predictions. Context uncertainties about future socio-economic developments are captured by combining MAUT with scenario planning. We perform a global sensitivity analysis (GSA) to assess the contribution of single uncertain preference parameters to the uncertainty of the ranking of alternatives. This is exemplified for sustainable water infrastructure planning in a case study in Switzerland. We compare 11 water supply alternatives ranging from conventional water supply systems to novel technologies and management schemes regarding 44 objectives. Their performance is assessed for four future scenarios and 10 stakeholders from different backgrounds and decision-making levels. Despite uncertainty in the ranking of alternatives, potential best and worst solutions could be identified. We demonstrate that a priori assumptions such as linear value functions or additive aggregation can result in misleading recommendations, unless thoroughly checked during preference elicitation and modeling. We suggest GSA to focus elicitation on most sensitive preference parameters. Our GSA results indicate that output uncertainty can be considerably reduced by additional elicitation of few parameters, e.g. the overall risk attitude and aggregation functions at higher-level nodes. Here, rough value function elicitation was sufficient, thereby substantially reducing elicitation time.
Scholten, L.; Schuwirth, N.; Reichert, P.; Lienert, J. (2015) Tackling uncertainty in multi-criteria decision analysis – an application to water supply infrastructure planning, European Journal of Operational Research, 242(1), 243-260, doi:10.1016/j.ejor.2014.09.044, Institutional Repository

How to make river assessments comparable: a demonstration for hydromorphology

River monitoring and assessment programs are important tools to quantify the condition of river ecosystems, identify deficits, and provide preliminary indication of how to improve them. But, they are limited in delivering comparable assessment results across national or transnational borders, aggregating site-specific assessments into broader scale assessments, and supporting river management decisions. We present a multi-criteria decision analysis approach for improving the comparability of ecological assessment methods of different origin and for combining these assessments into a joint procedure. The approach consists of seven consecutive steps. The most central ones concern the hierarchical allocation of ecological assessment endpoints, and the harmonization of the scoring procedure of attributes (ecological indicators or assets) to a common scale from 0 to 1. We demonstrate the approach integrating three programs developed to assess the hydromorphological river condition in Switzerland, Germany, and the USA. In our example, the integrated assessment produces comparable results for the whole range from natural to impacted rivers, while data continuity with original assessments was maintained. Our approach provides a common assessment standard due to the definition of the minimum amount of information required, is flexible regarding measurement and assessment endpoints, and bridges the gap between river quality assessment and management.
Langhans, S. D.; Lienert, J.; Schuwirth, N.; Reichert, P. (2013) How to make river assessments comparable: a demonstration for hydromorphology, Ecological Indicators, 32, 264-275, doi:10.1016/j.ecolind.2013.03.027, Institutional Repository

Methodological aspects of multi-criteria decision analysis for policy support: a case study on pharmaceutical removal from hospital wastewater

Decision making in public and political contexts can be complex. Multi-attribute value/utility theory (MAVT/MAUT) can support such decision processes by providing a transparent framework that helps focusing on objectives and corresponding degrees of achievement by different alternatives.
Eliciting preferences with MAVT/MAUT can be time consuming and cognitively challenging. Therefore, it might not be feasible to elicit full preference functions with standard methods. To deal with this problem, we suggest a simplified elicitation procedure that combines (a) the elicitation of values instead of utilities at lower-levels of the objectives hierarchy and conversion to utilities to consider risk attitudes at appropriate higher levels, (b) the use of linear value functions for sub-objectives with minor effects on the overall value, and (c) sensitivity analyses to check the robustness of results regarding these assumptions and the elicitation process in general. Furthermore, we developed a modified Swing procedure ("Reversed Swing2) to elicit weights for cases in which the hypothetical alternatives of the conventional Swing technique are unrealistic.
We applied this procedure to a case study on pharmaceutical removal from wastewater of a typical Swiss hospital involving 13 stakeholders. Aim of the interdisciplinary research group was to assess a large bundle of combinations of novel point source measures. The ultimate policy objective was to develop consensus solutions which are acceptable to all important stakeholder groups. We hope that the suggested simplified procedure stimulates the application of transparent and conceptually satisfying decision support methods in environmental management, which is needed to justify policy decisions to the public.
Schuwirth, N.; Reichert, P.; Lienert, J. (2012) Methodological aspects of multi-criteria decision analysis for policy support: a case study on pharmaceutical removal from hospital wastewater, European Journal of Operational Research, 220(2), 472-483, doi:10.1016/j.ejor.2012.01.055, Institutional Repository

Multi-criteria decision analysis: application examples

A participatory multi-criteria decision analysis framework reveals transition potential towards non-grid wastewater management

Many public environmental decisions are wicked problems due to high complexity and uncertainty. We test a participatory value-based framework based on multi-criteria decision analysis (MCDA) to tackle such problems. Our framework addresses two important gaps identified in reviews of MCDA applications to environmental problems: including stakeholders and treating uncertainty. We applied our framework in two complex real-world cases concerning a paradigm shift in the wastewater sector; the transition from centralized wastewater systems to decentralized non-grid systems. Non-grid systems may solve some problems of centralized systems by reducing costs, increasing flexibility, and addressing growing demands on environmental issues, especially in rural areas. But non-grid systems have rarely been implemented in OECD countries, because it is unclear whether a transition is recommendable, and whether stakeholders would accept this shift. This problem allows addressing several fundamental research questions. As theoretical contribution, we found that stakeholder participation in MCDA is necessary, because different preferences of stakeholders can lead to different best-performing options in the assessments. Compared to the typical integrated assessment (IA) approach that excludes stakeholders' preferences, the MCDA process led to clearer outcomes. Results indicate that including the uncertainty of predicted consequences of options with Monte Carlo simulation helped discriminate between options and identify best-performing options. Challenging the uncertainty of elicited stakeholder preferences with sensitivity analyses, we found that best-performing options were especially sensitive to the MCDA aggregation model. Despite the high uncertainty, it was possible to suggest robust consensus options that would perform reasonably well for all stakeholders. As practical contribution, results indicated that a transition from the centralized to decentralized non-grid systems seems feasible. Most stakeholders assigned highest weights to environmental protection objectives in decision-making workshops. These stakeholder preferences implemented in MCDA led to a generally better assessment of innovative non-grid systems, especially when including urine source separation. Stakeholders perceived the MCDA process as beneficial and found results plausible. We conclude that the proposed participatory value-based framework is rigorous, but still feasible in practice. The framework is certainly transferable to any context and is open to testing and refinement in various applications to wicked decision problems.
Beutler, P.; Larsen, T. A.; Maurer, M.; Staufer, P.; Lienert, J. (2024) A participatory multi-criteria decision analysis framework reveals transition potential towards non-grid wastewater management, Journal of Environmental Management, 367, 121962 (15 pp.), doi:10.1016/j.jenvman.2024.121962, Institutional Repository

Comparing PV-green and PV-cool roofs to diverse rooftop options using decision analysis

Flat roofs can employ a range of technologies to improve sustainability, such as photovoltaic (PV) panels, green roofs, cool roofs, or a combination of these options. Yet, weighing the benefits, costs, and performance of different roofing technologies is complex, especially when different stakeholders are involved. Decision analysis techniques, such as multi-criteria decision analysis (MCDA), can be used to systematically evaluate a diverse range of rooftop options to assess trade-offs in a quantitative way and avoid decision biases. This study offers a holistic comparison of different roof types, considering stakeholder preferences and uncertainty using MCDA. Ten flat roof options are compared, including black, gravel, cool, extensive green and semi-intensive green roofs, each with or without a rooftop PV installation, for nine objectives and three hypothetical stakeholder profiles. Performance is evaluated using building energy simulation, hydrologic modeling, and literature research. Uncertainty analyses are used to evaluate the effects of model assumptions on the MCDA results. For assumed preferences of an urban planner and environmentalist, semi-intensive green roofs with integrated PV installation are the best performing option; however, for a hypothetical building owner more concerned with costs, a gravel roof with PV ranks best. Uncertainty plays a role in the results, in particular, the uncertainty of the predicted outcome of options for the building owner, which can change the top-ranking options considerably. The uncertainty analyses are useful to identify consensus options over all three stakeholder types. Despite considerable uncertainty, extensive and semi-intensive green roofs with PV are recommended as relatively robust best-performing options.
Maurer, B.; Lienert, J.; Cook, L. M. (2023) Comparing PV-green and PV-cool roofs to diverse rooftop options using decision analysis, Building and Environment, 245, 110922 (15 pp.), doi:10.1016/j.buildenv.2023.110922, Institutional Repository
Lienert, J.; Andersson, J.; Hofmann, D.; Silva Pinto, F.; Kuller, M. (2022) How to co-design a flood early warning system (FEWS) for West Africa, Water Science Policy, (4 pp.), doi:10.53014/CBJJ5560, Institutional Repository

Innovative online survey about sustainable wastewater management: what young Swiss citizens know and value

Investigating wastewater management matters: in many OECD countries, the conventional centralized system is reaching its limits. Alternative decentralized options exist. Some directly affect citizens with in-house wastewater treatment. Involving citizens in decision processes would legitimate the outcome and facilitate implementation. However, citizen participation is challenging because they are numerous, and need to learn about the topic and construct their opinion. To include citizens, we propose an innovative online survey based on Multi-Attribute Value Theory (MAVT). Citizens receive value-focused information, and can communicate their preferences, captured as weights assigned to objectives. We collected quantitative and qualitative data, and elicited preferences from 184 young Swiss citizens, who will have to live with the decision outcome. In addition to reporting on insights for wastewater management, we assessed our survey, i.e. whether respondents learnt about the topic, constructed preferences, and understood the requirement to think in terms of objectives. Water quality and health protection mattered the most. The objectives directly concerning the respondents (time demand, attractiveness) were the least important. The best-ranked option in the subsequent Multi-Criteria Decision Analysis was a decentralized source separating system with dry toilets. Respondents were unaware that such decentralized options exist, indicating that learning about the topic occurred. Preferences were mostly newly constructed from no opinion, or pre-existing ones were reinforced. Our value-focused online survey helped citizens to understand the complex decision and construct their preferences. Swiss decision-makers, and beyond, should not be scared of a paradigm shift in wastewater management: the young generation seems ready to decentralize.
Aubert, A. H.; Schmid, S.; Beutler, P.; Lienert, J. (2022) Innovative online survey about sustainable wastewater management: what young Swiss citizens know and value, Environmental Science and Policy, 137, 323-335, doi:10.1016/j.envsci.2022.08.018, Institutional Repository

The role of multi-criteria decision analysis in a transdisciplinary process: co-developing a flood forecasting system in western Africa

Climate change is projected to increase flood risks in western Africa. In the FANFAR project, a pre-operational flood early warning system (FEWS) for western Africa was co-designed in workshops with 50–60 stakeholders from 17 countries, adopting multi-criteria decision analysis (MCDA). We aimed at (i) designing a FEWS with western African stakeholders using MCDA and (ii) evaluating participatory MCDA as a transdisciplinary process. To achieve the first aim (i), we used MCDA methods for problem structuring and preference elicitation in workshops. Problem structuring included stakeholder analysis, creating 10 objectives to be achieved by the FANFAR FEWS and designing 11 possible FEWS configurations. Experts predicted FEWS configuration performance, which we integrated with stakeholder preferences. We tested MCDA results in sensitivity analyses. Three FEWSs showed good performance, despite uncertainty, and were robust across different preferences. For stakeholders it was most important that the FEWS produces accurate, clear, timely, and accessible flood risk information. To achieve the second aim (ii), we clustered common characteristics of collaborative governance frameworks from the sustainability science and transdisciplinary literature. Our framework emphasizes issues crucial to the earth systems sciences, such as uncertainty and integrating interdisciplinary knowledge. MCDA can address both well. Other strengths of MCDA are co-producing knowledge with stakeholders and providing a consistent methodology with unambiguous, shared results. Participatory MCDA including problem structuring can contribute to co-designing a project but does not achieve later phases of transdisciplinary processes well, such as co-disseminating and evaluating results. We encourage colleagues to use MCDA and the proposed framework for evaluating transdisciplinary hydrology research that engages with stakeholders and society.
Lienert, J.; Andersson, J. C. M.; Hofmann, D.; Silva Pinto, F.; Kuller, M. (2022) The role of multi-criteria decision analysis in a transdisciplinary process: co-developing a flood forecasting system in western Africa, Hydrology and Earth System Sciences, 26(11), 2899-2922, doi:10.5194/hess-26-2899-2022, Institutional Repository

Potenzial dezentraler Abwassersysteme

Werterhalt und Bewirtschaftung von Kanalisation und ARA können kleine Gemeinden vor Herausforderungen stellen. Es gibt Alternativen, aber lohnen sich diese? Zwei Gemeinden wurden bei der strategischen Planung für ihr neues Abwassersystem unterstützt. Viele Ziele wurden als entscheidungsrelevant identifiziert, insbesondere Umweltschutzziele. Es zeigte sich, dass dezentrale Technologien mit Stoffstromseparierung die Anforderungen häufig besser erfüllen können als konventionelle Abwassersysteme.
Beutler, P.; Larsen, T. A.; Maurer, M.; Staufer, P.; Lienert, J. (2021) Potenzial dezentraler Abwassersysteme, Aqua & Gas, 101(1), 66-75, Institutional Repository

A mixed-methods approach to strategic planning for multi-benefit regional water infrastructure

Finding regional solutions for water infrastructure and other environmental management challenges requires coordination, communication, and a shared understanding among different stakeholders. To develop a more versatile and collaborative decision-making process for nutrient management in the San Francisco Bay Area, we used a mixed-methods approach consisting of stakeholder analysis with cluster analysis, multi-criteria decision analysis (MCDA), and scenario planning. These methods allowed us to identify agreements and disagreements in stakeholder objectives and preferences, clarify ways in which different options could meet the goals of diverse stakeholders, and elucidate how scientific uncertainty about technical performance and future conditions could affect management strategies. Results of the analysis indicate that several non-conventional nutrient management options like constructed wetlands and increased water recycling for irrigation met the goals of many stakeholders under a variety of future scenarios. A comparison of MCDA results with a more traditional 'cost-efficiency' measure (i.e., optimizing for the lowest cost per mass of nutrients removed) revealed little correlation between the two methods for stakeholders who expressed a preference for co-benefits of management options such as increased water supply and nutrient recovery for fertilizer use. The method also allowed us to identify key areas of disagreement (e.g., the relative importance of constructing infrastructure that would not be affected by sea level rise) that should find regulatory or professional consensus before advancing with decision-making. This mixed-methods approach is time-consuming and requires specific expertise that is not always available to stakeholders. The development of more efficient preference elicitation and interaction procedures would increase the likelihood that decision-makers would make the extra effort required to use this potentially powerful method. Nonetheless, the mixed-methods approach had several important advantages over more traditional strategic planning methods including its ability to stimulate discussions amongst stakeholders who do not regularly interact, support collaborative planning, and encourage multi-benefit solutions.
Harris-Lovett, S.; Lienert, J.; Sedlak, D. (2019) A mixed-methods approach to strategic planning for multi-benefit regional water infrastructure, Journal of Environmental Management, 233, 218-237, doi:10.1016/j.jenvman.2018.11.112, Institutional Repository

A scenario-based MCDA framework for wastewater infrastructure planning under uncertainty

Wastewater infrastructure management is increasingly important because of urbanization, environmental pollutants, aging infrastructures, and climate change. We propose a scenario-based multi-criteria decision analysis (MCDA) framework to compare different infrastructure alternatives in terms of their sustainability. These range from the current centralized system to semi- and fully decentralized options. Various sources of uncertainty are considered, including external socio-economic uncertainty captured by future scenarios, uncertainty in predicting outcomes of alternatives, and incomplete preferences of stakeholders. Stochastic Multi-criteria Acceptability Analysis (SMAA) with Monte Carlo simulation is performed, and rank acceptability indices help identify robust alternatives. We propose step-wise local sensitivity analysis, which is useful for practitioners to effectively elicit preferences and identify major sources of uncertainty. The approach is demonstrated in a Swiss case study where ten stakeholders are involved throughout. Their preferences are quantitatively elicited by combining an online questionnaire with face-to-face interviews. The trade-off questions reveal a high concern about environmental and an unexpectedly low importance of economic criteria. This results in a surprisingly good ranking of high-tech decentralized wastewater alternatives using urine source separation for most stakeholders in all scenarios. Combining scenario planning and MCDA proves useful, as the performance of wastewater infrastructure systems is indeed sensitive to socio-economic boundary conditions and the other sources of uncertainty. The proposed sensitivity analysis suggests that a simplified elicitation procedure is sufficient in many cases. Elicitation of more information such as detailed marginal value functions should only follow if the sensitivity analysis finds this necessary. Moreover, the uncertainty of rankings can be considerably reduced by better predictions of the outcomes of alternatives. Although the results are case based, the proposed decision framework is generalizable to other decision contexts.
Zheng, J.; Egger, C.; Lienert, J. (2016) A scenario-based MCDA framework for wastewater infrastructure planning under uncertainty, Journal of Environmental Management, 183(3), 895-908, doi:10.1016/j.jenvman.2016.09.027, Institutional Repository

Wasserinfrastrukturen nachhaltig in eine unsichere Zukunft führen

Die Wasserversorgung und Abwasserentsorgung sind Generationenbauwerke mit langer Lebensdauer und entsprechend langen Planungshorizonten. Wie können wir ihre Leistungen nachhaltig in die Zukunft führen? Wie gehen wir mit den Unsicherheiten um? Wie beziehen wir die Nachhaltigkeit quantitativ in unsere Planungsansätze ein? Im Rahmen des nationalen Forschungsprogramms 61 ging die Eawag diesen Fragen nach.
Maurer, M.; Lienert, J. (2014) Wasserinfrastrukturen nachhaltig in eine unsichere Zukunft führen, Eawag News [dtsch. Ausg.], 1-8, Institutional Repository

Multikriterielle Entscheidungsanalyse. Neue Ansätze für langfristige Infrastrukturplanung in der Wasserver- und -entsorgung

Im NFP-61-Forschungsprojekt «Langfristige Planung nachhaltiger Wasserinfrastrukturen» der Eawag wurden für die Planung der Wasserver- und Abwasserentsorgung unterschiedliche Alternativen miteinander verglichen. Die multikriterielle Entscheidungsanalyse berücksichtigt dabei die Präferenzen der Akteure und die Szenarienanalyse testet die Robustheit der Alternativen gegenüber unsicheren Zukunftsentwicklungen. Dieser neue Ansatz ergänzt die generelle Wasserversorgungsplanung (GWP) sowie die generelle Entwässerungsplanung (GEP) und bringt die Infrastrukturplanung auf eine nachhaltige Basis.
Scholten, L.; Egger, C.; Zheng, J.; Lienert, J. (2014) Multikriterielle Entscheidungsanalyse. Neue Ansätze für langfristige Infrastrukturplanung in der Wasserver- und -entsorgung, Aqua & Gas, 94(5), 62-69, Institutional Repository

Strategic rehabilitation planning of piped water networks using multi-criteria decision analysis

To overcome the difficulties of strategic asset management of water distribution networks, a pipe failure and a rehabilitation model are combined to predict the long term performance of rehabilitation strategies. Bayesian parameter estimation is performed to calibrate the failure and replacement model based on a prior distribution inferred from three large water utilities in Switzerland. Multi criteria decision analysis (MCDA) and scenario planning build the framework for evaluating 18 strategic rehabilitation alternatives under future uncertainty. Outcomes for three fundamental objectives (low costs, high reliability, and high intergenerational equity) are assessed. Exploitation of stochastic dominance concepts helps to identify twelve non dominated alternatives and local sensitivity analysis of stakeholder preferences is used to rank them under four scenarios. Strategies with annual replacement of 1.5 2% of the network perform reasonably well under all scenarios. In contrast, the commonly used reactive replacement is not recommendable unless cost is the only relevant objective. Exemplified for a small Swiss water utility, this approach can readily be adapted to support strategic asset management for any utility size and based on objectives and preferences that matter to the respective decision makers.
Scholten, L.; Scheidegger, A.; Reichert, P.; Mauer, M.; Lienert, J. (2014) Strategic rehabilitation planning of piped water networks using multi-criteria decision analysis, Water Research, 49(1), 124-143, doi:10.1016/j.watres.2013.11.017, Institutional Repository

Multiple-criteria decision analysis reveals high stakeholder preference to remove pharmaceuticals from hospital wastewater

Point-source measures have been suggested to decrease pharmaceuticals in water bodies. We analyzed 68 and 50 alternatives, respectively, for a typical Swiss general and psychiatric hospital to decrease pharmaceutical discharge. Technical alternatives included reverse osmosis, ozonation, and activated carbon; organizational alternatives included urine separation. To handle this complex decision, we used Multiple-Criteria Decision Analysis (MCDA) and combined expert predictions (e.g., costs, pharmaceutical mass flows, ecotoxicological risk, pathogen removal) with subjective preference-valuations from 26 stakeholders (authorities, hospital-internal actors, experts). The general hospital contributed ca. 38% to the total pharmaceutical load at the wastewater treatment plant, the psychiatry contributed 5%. For the general hospital, alternatives removing all pharmaceuticals (especially reverse osmosis, or vacuum-toilets and incineration), performed systematically better than the status quo or urine separation, despite higher costs. They now require closer scrutiny. To remove X-ray contrast agents, introducing roadbags is promising. For the psychiatry with a lower pharmaceutical load, costs were more critical. Stakeholder feedback concerning MCDA was very positive, especially because the results were robust across different stakeholder-types. Our MCDA results provide insight into an important water protection issue: implementing measures to decrease pharmaceuticals will likely meet acceptance. Hospital point-sources merit consideration if the trade-off between costs and pharmaceutical removal is reasonable.
Lienert, J.; Koller, M.; Konrad, J.; McArdell, C. S.; Schuwirth, N. (2011) Multiple-criteria decision analysis reveals high stakeholder preference to remove pharmaceuticals from hospital wastewater, Environmental Science and Technology, 45(9), 3848-3857, doi:10.1021/es1031294, Institutional Repository

Charting a path for innovative toilet technology using multicriteria decision analysis

Practical and theoretically sound methods for analyzing innovative environmental technologies are needed to inform public and private decisions regarding research and development, risk management, and stakeholder communication. By integrating scientific assessments with a characterization of values, multicriteria decision analysis (MCDA) supports the ranking of alternative technology pathways on the basis of technical, financial, and social concerns. We applied MCDA to evaluate the use of NoMix urine separating toilets for managing environmental risk and postponing expensive upgrades to a large wastewater treatment plant near Zürich, Switzerland. Results indicate that, given current priorities, no single, fixed course of action (including the status quo) will be desirable to all stakeholders over the considered time horizon. However, a path forward is suggested that is not significantly disadvantageous to any stakeholder now and leaves open future options, allowing society to achieve overall greater benefits if priorities change, new environmental risks are revealed, or technology improves. While our analysis focuses on a particular catchment in Switzerland, many communities worldwide are faced with an aging and inefficient wastewater treatment infrastructure while also experiencing growth and development. Our framework can help these communities balance the conflicting objectives of diverse stakeholders and gain insight into the role that urine separation can play in transitioning to a more comprehensive and sustainable urban water management system.
Borsuk, M. E.; Maurer, M.; Lienert, J.; Larsen, T. A. (2008) Charting a path for innovative toilet technology using multicriteria decision analysis, Environmental Science and Technology, 42(6), 1855-1862, doi:10.1021/es702184p, Institutional Repository

Other decision support approaches

Creating effective flood warnings: a framework from a critical review

As climate change is intensifying the frequency and severity of floods around the globe, adaptation is increasingly vital. Besides structural measures to mitigate flood risk, non-structural measures are known to be highly effective and low-cost. Such non-structural measures include Flood Early Warning Systems (FEWS). Effective warning creation and dissemination are crucial to successful FEWS. Despite extensive bodies of research that cross the boundaries between disciplines and application domains, systematic understanding of the detailed aspects contributing to the effectiveness of flood warnings is lacking. We systematically review the state-of-the-art in risk perception and warning communication present in academic (and grey) literature for FEWS. We focus on the elements of risk warnings specifically, rather than reviewing the topic of risk communication in general. We start with exploring how personal attributes affect individual risk perception related to flood warnings. We then deconstruct flood warnings into three basic components: content, format and dissemination channel. Most importantly, we found 21 individual elements (options) for these components, each associated with varying levels of support for their effectiveness in literature. Important caveats were identified, such as a lack of research into the speech format and SMS channel. We then describe and visualise the warning creation process, providing a framework for guidance. Accelerating technological advancement necessitates continued research into the effectiveness of novel formats and channels, rendering the currently most widely supported and researched elements increasingly obsolete. Further research is needed to explore the complex interplay between elements, i.e., how do different combinations impact effectiveness? Finally, little is known about the transferability of our findings to Africa, Asia and South America, as industrialised countries dominate the research. We hope our findings will contribute to improved understanding, and support the practice of creating effective flood warnings.
Kuller, M.; Schoenholzer, K.; Lienert, J. (2021) Creating effective flood warnings: a framework from a critical review, Journal of Hydrology, 602, 126708 (16 pp.), doi:10.1016/j.jhydrol.2021.126708, Institutional Repository

Testing fairness principles for public environmental infrastructure decisions

Public infrastructure decisions affect many stakeholders with various benefits and costs. For public decisions, it is crucial that decision-making processes and outcomes are fair. Fairness concepts have rarely been explored in public infrastructure planning. We close this gap for a global issue of growing importance: replacing sewer-based, centralized by decentralized wastewater systems. We empirically study fairness principles in this policy-relevant context, and identify possible influencing factors in a representative online survey of 472 Swiss German residents. In a transition phase, innovative, decentralized pilot wastewater systems are installed in households. We designed two vignettes for this context to test the adhesion to principles of distributive justice—equality, equity, and need—at individual and community levels. A third vignette tests procedural justice with increasing fulfilment of fair process criteria. The results confirm our hypotheses: equity is perceived as fairer than equality at individual and collective levels. Contrary to expectations and literature, need is perceived as even fairer than equity. Procedural justice results confirm literature, e.g., the majority (92%) of respondents deems a policy fair that includes them in decision-making. Only few demographic and explanatory factors are significantly correlated with respondents' fairness perceptions. Although unexpected, this is positive, implying that introducing decentralized wastewater technology can be designed for the entire population independent of characteristics of individuals. Generally, our results confirm literature: fairness perceptions depend on the circumstances. Hence, they should be elicited in the exact application context to be able to enter negotiation processes and provide concrete advice to decision makers.
Schmid, S.; Vetschera, R.; Lienert, J. (2021) Testing fairness principles for public environmental infrastructure decisions, Group Decision and Negotiation, 30, 611-640, doi:10.1007/s10726-021-09725-2, Institutional Repository

Climate change and the willingness to pay to reduce ecological and health risks from wastewater flooding in urban centers and the environment

Climate change scenarios predict an increase of extreme rain events, which will increase the risk of wastewater flooding and of missing legal water quality targets. This study elicits the willingness to pay to reduce ecological and health risks from combined sewer overflows (CSOs) in rivers and lakes, and wastewater flooding of residential and commercial zones under the uncertainty of climate change. We implement a discrete choice experiment on a large representative sample of the Swiss population. We find that about 71% of the respondents are willing to pay a higher annual local tax to reduce the risk of CSOs in rivers and lakes. Swiss households strongly value the protection of water bodies, and mostly, the avoidance of high ecological risks and health risks for children related to CSOs in rivers and lakes. Our findings also show that climate change perception has a significant effect on the willingness to pay to reduce these risks. These results are important to support policy makers' decisions on how to deal with emerging risks of climate change in the water sector and where to set priorities.
Veronesi, M.; Chawla, F.; Maurer, M.; Lienert, J. (2014) Climate change and the willingness to pay to reduce ecological and health risks from wastewater flooding in urban centers and the environment, Ecological Economics, 98, 1-10, doi:10.1016/j.ecolecon.2013.12.005, Institutional Repository

Meeting the challenges of transdisciplinary knowledge production for sustainable water governance

Increasing pressure on mountain water resources is making it necessary to address water governance issues in a transdisciplinary way. This entails drawing on different disciplinary perspectives, different types of knowledge, and different interests to answer complex governance questions. This study identifies strategies for addressing specific challenges to transdisciplinary knowledge production aiming at sustainable and reflective water governance. The study draws on the experiences of 5 large transdisciplinary water governance research projects conducted in Austria and Switzerland (Alp-Water-Scarce, MontanAqua, Drought-CH, Sustainable Water Infrastructure Planning, and an integrative river management project in the Kamp Valley). Experiences were discussed and systematically analyzed in a workshop and subsequent interviews. These discussions identified 4 important challenges to interactions between scientists and stakeholders—ensuring stakeholder legitimacy, encouraging participation, managing expectations, and preventing misuse of data and research results—and explored strategies used by the projects to meet them. Strategies ranged from key points to be considered in stakeholder selection to measures that enhance trustful relationships and create commitment.
Renner, R.; Schneider, F.; Hohenwallner, D.; Kopeinig, C.; Kruse, S.; Lienert, J.; Link, S.; Muhar, S. (2013) Meeting the challenges of transdisciplinary knowledge production for sustainable water governance, Mountain Research and Development, 33(3), 234-247, doi:10.1659/MRD-JOURNAL-D-13-00002.1, Institutional Repository

Decision support in urban water management based on generic scenarios: the example of NoMix technology

Urine source separation (NoMix technology) followed by processing the concentrated nutrient solution has the potential to become a cost-efficient alternative to conventional end-of-pipe nutrient elimination. A choice of processing technologies can only be made for specific scenarios, and there is currently no methodology for analyzing generic situations. In setting up a formalized decision-support methodology (based on STEEPLED analysis), we discuss how to create such generic scenarios, how to couple them with process engineering objectives, how to define the technology requirements, and finally how to produce a realistic subset of technology alternatives. The methodology is tested in five real scenarios. We also touch on the criteria for a final choice of technology taking into account large uncertainties about the performance of real technologies. We conclude that technology development is one of the most important requirements for implementing urine source separation in practice. There is an urgent need to develop cost-efficient processing technologies that satisfy the requirements of stakeholders.
Larsen, T. A.; Maurer, M.; Eggen, R. I. L.; Pronk, W.; Lienert, J. (2010) Decision support in urban water management based on generic scenarios: the example of NoMix technology, Journal of Environmental Management, 91(12), 2676-2687, doi:10.1016/j.jenvman.2010.07.032, Institutional Repository

Awards

2020

Haag, F., Reichert, P., Maurer, M., Lienert, J. Decision Analysis Society (DAS) of INFORMS Student Paper Award 2020 for the paper: Integrating uncertainties of preferences and predictions in decision models: An application to regional wastewater planning. Journal of Environmental Management 252: 109652.
Paper: https://doi.org/10.1016/j.jenvman.2019.109652.
Award: https://www.informs.org/Recognizing-Excellence/Community-Prizes/Decision-Analysis-Society/DAS-Student-Paper-Award.

 

2019

Haag, F., Lienert, J., Schuwirth, N, Reichert, P. OMEGA Best Paper Award 2019: Identifying non-additive multi-attribute value functions based on uncertain indifference statements. OMEGA 85: 49-67.
Paper: https://www.sciencedirect.com/science/article/pii/S0305048317308204.
Award: http://www.omegajournal.org/authors.html.

 

2019

Marttunen, M., Lienert, J., Belton, V. EURO Award for the Best EJOR Paper. Review: Structuring Problems for Multi-Criteria Decision Analysis in practice: A literature review of method combinations. Association of European Operational Research Societies, 30th EURO Conference, Dublin, Ireland, 26.06.2019.
Paper: https://www.sciencedirect.com/science/article/pii/S0377221717303880?via%3Dihub.
Award: https://www.euro-online.org/web/pages/1647/eabep-winners-2019.

Teaching

ETH Zürich, Department of Environmental Systems Science

ETH Zürich, Institute of Environmental Engineering, Chair of Ecological Systems Design