A parallel implementation of the PROMETHEE method

The obtainment of a result from a decision support system is usually preceded by a structuring of the decision situation and followed by a robustness analysis phase. In this last phase the decision makers (DMs) observe the impact of changing the parameters of the decision model built during structuring, in order to learn about the situation and increase their confidence on the results. It is essential that the decision support system enables interactivity (i.e. provides short response times), otherwise during this phase the DMs will not be encouraged to be as exhaustive as required by the situation. This presents a computational challenge when the problems are not of trivial dimension. This paper discusses the application of parallel processing as a means to meet this challenge when building a decision support system based on the PROMETHEE multicriteria aid method. Several parallel programs have been built and compared on a 16-processor computer. Our purpose was to acquire some insight on how the parallel programs do perform under different situations and to identify the features of the method more relevant to its parallelisation. We verified that at some situations the reduction of the computer's response time by means of parallel processing is quite appreciable and may foster the use of a decision support tool.