An approach to the design of a hybrid organization of workshops into functional layout and group technology cells

Abstract

Cell formation is a widely recognized way of structuring certain types of manufacturing systems so as to improve their efficiency. Unfortunately, in many cases, the characteristics of the workshop are such that grouping certain machines into cells would actually improve the performance of the shop, but certain other machines would be more efficiently used in functional cells (i.e. cells composed of machines of the same type). The resulting organization is called ‘hybrid’. The problem addressed here is how to define the cells of a workshop so as to design a hybrid system? We suggest a constrained multi-criteria approach, which favours cells for the parts that are regularly manufactured over time (i.e. stable parts) and that have a great contribution to the traffic of parts in the workshop. This problem is addressed using evolutionary computation. An evolutionary programming algorithm is proposed and illustrated on a test example with a known optimum.