Decision support systems design as knowledge-based tool integration

Decision making is always a topical problem. In order to make a decision, a decision maker needs criteria and has to analyze the problem with these criteria. But it is not simple to take into account a great deal of criteria in order to make a decision. In general, one tool gives one analysis for one criterion (except the multicriteria tools). The paper aims to present a method of designing DSS based on most analysis tools. A main feature of this method is to decompose the problem into subproblems in order to distinguish the tools associated to each subproblem. The main goal is to reuse existing tools corresponding to these subproblems. The interesting feature of our method is that the DSS is not dependent on the components. So, other components could be added to the system in the future without having to rethink the system´s architecture. This method is currently being applied to DSS in railway investment. We see that the resulting synthesis of tools is difficult to make in order to give a real decision support.