Decision Analysis Using Rough Sets

We show that the rough set theory is a useful tool for analysis of decision situations, in particular multi-criteria sorting problems. It deals with vagueness in the representation of a decision situation, caused by granularity of the representation. The rough set approach produces a set of decision rules involving a reduced number of most important criteria. It does not correct vagueness manifested in the representation; instead, the rules produced are categorized into deterministic and non-deterministic. The set of decision rules explains the decision situation and may be used to support new decisions. An example illustrates the rough set analysis of a multi-criteria sorting problem.