Indexes for fixed and flexible environmental target setting: a decision analytical perspective

We describe a decision-analytical, structured approach for developing envir onmental indexes, ensuring them to be explicit and problem-specific. The in dexes are used for setting and communicating targets related to a product's environmental performance. Two index models are the fixed model, based on the prevailing tradition, where announced targets must be met in every impa ct category, and the flexible model, where impacts are aggregated and a tar get is announced in terms of the aggregated impact, thus enabling trade-off s between the impacts. The flexible model is a new and promising approach, which offers more freedom to reach the target even though more preference i nformation must be modelled. We stress the different viewpoints of those us ing the index for target setting and of those whose products are evaluated with the index. We do this by differentiating between impacts and stressors and expressing the targets in terms of both. We illustrate the approaches with a hypothetical environmental labelling example.