Decision aid systems for evaluating sustainability: a critical survey

Assessing sustainability in compliance with the EU water framework directive is affected by numerous conflicting interests. As they can no longer be resolved by means of intuitive reasoning, some authors propose the integration of the major fragmented indicators into one common indicator of the overall sustainability by means of a codified multi-criteria decision support methodology (DSM). Practitioners in urban water management, however, usually object to the use of a codified DSM, as in the legal context (negotiations between the stakeholders, tendering procedure) it might jeopardize the feasibility of the decision making process (DMP). Here we show that a feasible implementation of a DSM into the DMP is possible. To this end, we design a cooperative approach, which by means of an axiomatic evaluation helps to select an appropriate DSM. We illustrate it by a hypothetical dialogue between the relevant authority and the developer. It will expose the inherent limitations of the DSM, which are due to their underlying mathematical features.