The Inter Class Traffic Minimization Method (ICTMM) that arranges the production equipment of a machine shop into manufacturing cells in order to minimize the inter cell trafflc of parts is presented in this paper. All quantitative tasks of this method are performed by algorithms that are embedded in a knowledge base. The aggregation rules and the problem constraints form the core of this knowledge base. Two other methods of factory flow analysis are also presented in order to compare their criteria and objectives to the ICTMM. Finally, all three systems are applied to a large size industrial project and the results obtained are presented and evaluated. We conclude by suggesting further research directions for a most comprehensive solution to the layout of a cellular manufacturing facility.