THE SHORT-TERM SCHEDULING OF MULTIPRODUCT SINGLESTAGE BATCH PLANTS WITH PARALLEL LINES PART TWO: REDUCTION OF THE MODEL

The first part of this paper presents a model for the short-term scheduling of multiproduct singlestage batch plants with parallel lines. Then, in this part, some heuristic rules are introduced into the model based on the characteristics of the model and multiproduct singlestage batch plants. The rational usage of these heuristic rules can reduce the number of 0-1 variables, continuous variables and constraints, so that the formulation of the model is tighter and the computational effort is greatly reduced. Furthermore, the heuristic rules have no effect on the optimality of the model. A large number of computational examples show that the optimal scheduling can be obtained by solving MILP model in a reasonable short time, especially when the scheduling problem involving several identical orders is considered.