SCHEDULING OF MULTIPURPOSE BATCH CHEMICAL-PLANTS .2. MULTIPLE-PRODUCT CAMPAIGN FORMATION AND PRODUCTION PLANNING

An efficient procedure to identify the dominant multiple-product campaigns for multipurpose batch chemical plants is presented. On the basis of a linear dominance property, the dominant campaigns are identified as the noninferior extreme points of the associated multiobjective campaign formation problem. The noninferior set estimation method has been incorporated into a decomposition strategy which alternately solves an equipment group master problem to identify dominant equipment group profiles for the production lines of the campaign and a campaign formation subproblem with identifies the dominant campaigns for a particular equipment group profile. A multiperiod mixed integer linear programming production planning model for multipurpose batch plants that allots the available production time to a subset of the dominant campaigns and accounts for lost production time due to changeovers and startup times is also presented. The campaign formation and production planning procedures are illustrated with an example problem.