Optimization of the multi-objective dynamic cell formation problem considering machine sharing

The design of cell formation of a cellular manufacturing system (CMS) is a combinatorial optimization problem. Cellular manufacturing can reduce the material handling costs and increase the efficiency of the system. Because of uncertainties in production life circle, there are many changes in demand of the products. But former cell formation methods ignore this situation. And product life cycles are shorter and shorter, and demand volumes and product types are hard to forecast. Thus, cell design needs to be suitable for different periods. Dynamic cell formation is a solution of this problem. In this paper, a multi-objective model of Dynamic cell formation is presented to optimal the relocation cost, machine utilization and intercell moves. Besides this, the situation that some machine need be shared at more than one cell at the same period is also considered. To solve the mathematical model, a genetic algorithmis applied and two numerical examples are presented to evaluate the validity of this model.