A new continuous-time MILP model for the short term scheduling of multipurpose batch plants with due dates is presented. The proposed model is a general State Task Network (STN) formulation that accounts for variable batch sizes and processing times, various storage policies (UIS/FIS/NIS/ZW), utility constraints (other than units), and allows for batch mixing and splitting. Its key features are: (a) a continuous, common for all units time partitioning, (b) assignment constraints are expressed using only the binary variables defined for tasks, (c) start times of tasks are eliminated, (d) a new class of tightening valid inequalities is added to the MILP formulation, and (e) a new disjunctive programming formulation is used for the matching of due dates with time points. The proposed model is more general than the previously reported models and is computationally efficient.
All Science Journal Classification (ASJC) codes
- Chemical Engineering(all)
- Computer Science Applications
- Multipurpose batch plants
- Scheduling with due dates