Time-phased creation of hybrid manufacturing systems

This paper develops a comprehensive method for transforming pure functional manufacturing shops into hybrid production systems that comprise both cellular and functional areas. The facility redesign approach first derives the layout of the work centers within each cell and then places the cells within existing departments according to a time-phased implementation plan. The incremental cell implementation is dictated by budget constraints that limit the allowable investment in each fiscal period. The goal is to maximize the net benefit from cell implementation, expressed as the difference between the savings in material handling effort and the cost of machine rearrangement. An explicit enumeration scheme provides the optimal intra-cell layout. The problems of cell placement and implementation sequence are integrated in an integer programming formulation. The decomposition of the mathematical model motivates a space search approach, which generates an optimal solution. All algorithms are integrated and used to transform the functional shop of a large manufacturer into a hybrid production area. The results illustrate that substantial benefits can be realized even with a conservative multiperiod implementation plan.