ITERATIVE PROCEDURES FOR MULTIPERIOD ORDER SELECTION AND LOADING PROBLEMS IN FLEXIBLE MANUFACTURING SYSTEMS

This paper focuses on multi-period order selection and loading problem s in flexible manufacturing systems. The multi-period order selection problem is the problem of selecting orders to be produced in each peri od during the upcoming planning horizon, and the loading problem invol ves allocation of operations and required tools to machines for orders selected in each period. The objective is to minimize earliness and t ardiness costs and subcontracting costs. The earliness and tardiness c osts are incurred if an order is not finished on time, while subcontra cting cost is incurred if an order is not selected within the planning horizon (and must be subcontracted) due to limits in processing time capacity and the tool magazine capacity of the machines. To solve the two problems simultaneously, we develop four iterative procedures in w hich the multi-period order selection and loading problems are solved repeatedly until a good solution is obtained. To compare the four iter ative procedures, computational experiments are done on randomly gener ated test problems and the results are reported.