Mixed-integer linear programming model for short-term scheduling of a special class of multipurpose patch plants

In this paper, a mathematical formulation for the short-term scheduling of a sequential multipurpose batch plant is proposed. The scheduling problems of the multipurpose batch plants under a mixed product campaign (MPC) are a ddressed here. A mixed-integer linear programming (MILP) model is developed based on the time slot, which is used to determine the production sequence and the production path of each batch. In order to reduce the search space , we propose a heuristic method that relies on the use of preordering const raints. Application of the preordering constraints to the proposed MILP mod el reduced the computational time required by more than 40%. The proposed m odel is extended to sequential multipurpose batch plants with parallel unit s.