As is generally recognized, no multiple criteria decision analysis (MCDA) technique is the “best” for all problems and the various methods often produce different results for the same problem (e.g., [5,7]). Typically the differences are greater when there are more alternatives and when the alternatives have similar values for the criteria [15]. Therefore, the application of distinct MCDA methods, with different underlying assumptions, is likely to generate more confidence in the results obtained with distinct approaches. Since it has been recognized that DSS incorporating complex models and methods have been “underutilized”[2] and DMs reveal reluctant to use potentially beneficial tools due to their perceived complexity, MCPUIS incorporates simple methods based on distinct underlying principles which are easy to be explained having in mind not just the system acceptance but also reliance on the results. However, as this is an independent module (external to the GIS, RDBMS and human-computer interface), it may accommodate additional methods to be implemented in a future phase of development.