Anders Vestergaard Jensen

Modelling decision support and uncertainty for large transport infrastructure projects: The CLG-DSS model of the Øresund Fixed Link

This paper presents a decision support system, named the CLG-DSS model, which makes it possible for decision makers to assess various uncertainties in project appraisal in a systematic and explicit way. This model, a decision support system (DSS) developed within the Danish Centre for Logistics and Freight Transport (CLG) is based on cost-benefit analysis (CBA) embedded in a wider multi-criteria analysis (MCA) by the use of some principles for composite modelling assessment (COSIMA). The CLG-DSS model is set up to make use of scenario analysis (SA) and Monte Carlo simulation (MCS). A particular concern in the model is the handling of varying information across the assessment criteria and the application of SA to inform the MCS parameter setting. After the presentation of the modelling principles some ex-post case calculations for the Oresund Fixed Link are illuminating different aspects of appraisal uncertainty and thereby, at the same time, demonstrate the features of the CLG-DSS model as a useful decision support tool. It is finally concluded that appraisal of large infrastructure projects can be effectively supported by dealing with uncertainty issues in accordance with the principles described.

Examination of Decision Support Systems for Composite CBA and MCDA Assessments of Transport Infrastructure Projects

This paper examines decision support systems (DSS) for composite appraisals of transport infrastructure projects comprising both cost-benefit analysis (CBA) and multi-criteria decision analysis (MCDA). Two DSS, REMBRANDT and COSIMA, are in this context examined and compared using a case study dealing with alternatives for a new high-speed railway line in Sweden. The REMBRANDT system is based on multiplicative value functions and makes use of pair wise comparisons on both attribute and criteria level. The COSIMA system is based on additive value functions and makes use of the REMBRANDT technique using pair wise comparisons on attribute level and swing weights on criteria level. One difference between the two approaches is the focus the COSIMA system puts on combining the CBA and MCDA results influencing, among other things, the way that the final results are expressed. Finally, a recommendation for the use of DSS within transport infrastructure appraisals is set out.

Estimating the Robustness of Composite CBA and MCA Assessments by Variation of Criteria Importance Order

This paper discusses the concept of using rank variation concerning the stakeholder prioritising of importance criteria for exploring the sensitivity of criteria weights in multi-criteria analysis (MCA). Thereby the robustness of the MCA-based decision support can be tested. The analysis described is based on the fact that when using MCA as a decision-support tool, questions often arise about the weighting (or prioritising) of the included criteria. This part of the MCA is seen as the most subjective part and could give reasons for discussion among the decision makers or stakeholders. Furthermore, the relative weights can make a large difference in the resulting assessment of alternatives (Hobbs and Meier 2000). Therefore it is highly relevant to introduce a procedure for estimating the importance of criteria weights. This paper proposes a methodology for estimating the robustness of weights used in additive utility models.