Possibilistic Programming and Gas for Aggregate Production Planning under Vague Information

In production planning activities, aggregate planning is surely the phase where the lack of information is more relevant. The reasons for that can be summarised in: a) the planning product is an aggregate one, very often not corresponding to actual products; b) the delay from the actual production is relevant so that information regarding actual production resources availability and performances are vague; c) the planning activity is often based on forecasts. On the other hand, all the subsequent production planning activities are based on the result of aggregate planning. In the paper a research going on at the Workgroup for Soft Computing Application in Manufacturing is presented. A Decision Support System (DSS) for assisting the decision maker in Aggregate Production Planning decisions in a vague environment has been developed using possibilistic formulation. First results are presented and discussed.