Hybrid capacity modeling for alternative machine types in linear programming production planning

Processing by alternative machines is very common in today's manufacturing environment, especially in the semiconductor industry. Leachman and Carmon (1992) have presented a novel approach to model alternative machine capacit ated problems for Linear Programming (LP) production planning. Their approa ch makes possible the modeling of complex processes with re-entry into alte rnative machines in large scale LP production planning. However, there are difficulties in using their approach in industrial applications. In order t o use their approach, a uniform assumption must be satisfied. But in many i ndustrial applications, this assumption cannot be satisfied. In addition, t heir approach creates new alternative machine sets by performing union oper ations on existing alternative machine sets with common machine types. This will increase the number of capacity constraints, which may increase the s olution time of the LP formulation. This study compares their approach and the partition approach outlined herein in terms of CPU times used. Finally, this study proposes a hybrid capacity modeling approach that is more suita ble for industrial applications.