SCHEDULING METHOD IN DESIGN OF MULTIPURPOSE BATCH PLANTS WITH CONSTRAINED RESOURCES

A scheduling method that incorporates the design of multipurpose batch plants is developed. The scheduling consists of two interactive sub-p roblems: production scheduling and constrained resources scheduling, a nd on-site work is one of the typical constrained resources. In the de sign of these plants, the optimal schedule should be made within a sho rt time, and cyclic scheduling according to the cycle production is ap propriate. An IP (Integer Programing) model is suitable for such short -term scheduling, and the scheduling method is developed on the basis of the previous IP model for production scheduling. To make the optima l schedule, the allocation and sequence of tasks of on-site work shoul d be optimized in relation with the production scheduling. In this stu dy, the required properties of the on-site work scheduling in design i s considered, and this sub-problem is converted into an assignment pro blem. The on-site work is defined in linear constraints with integer v ariables describing the task assignments. Moreover, the on-site work i s newly defined in the production scheduling, and these definitions ar e related by the introduced integer variables. Finally, the effectiven ess of the developed scheduling method is demonstrated by an example p roblem.