A concurrent approach to cell formation and assignment of identical machines in group technology

Abstract

In designing a cellular manufacturing system, an important way to reduce and simplify intercell flows is to identify shared machines and duplicate them to some cells. However, the shared machines may not be properly identified by the existing cell formation methods. Thus, some unnecessary machine duplication may be made in the sense of capacity requirement and capital investment. In fact, for practical applications, the number of machines of a machine type should be determined by the capacity requirement of the parts to be produced in the system, and should be the constraint for the cell formation problem. Therefore, multiple identical machines should be appropriately assigned into different cells in designing a cellular manufacturing system. To overcome this drawback of the existing methods, in this paper a network model is developed for the design of a cellular manufacturing system. In the model, the machine type which has only one machine is represented by a simple node. The machine type which has two or more machines is represented by a complex node. Thus, this model can describe multiple machines of the same type. Based on this model, a new approach is presented. By the proposed approach, the cell formation problem and the proper assignment of identical machines are solved concurrently. Therefore, the proposed approach provides a more effective solution than the existing methods.