This paper describes IDSSFlex, a computer system for the analysis and evaluation of Flexible Manufacturing System (FMS) design configurations. IDSSFlex is an intelligent decision support system which selects from among several configurations and control strategy alternatives of design, the most appropriate one for a specific case. In order to accomplish such an objective, the system presents simultaneously the following features: ability to quantify subjective factors, ability to account for individual preferences, and ability to cope with multiple criteria decision making. A case study illustrates the effectiveness of the computer system.