Scheduling of multistage multiproduct chemical batch plants using a constraint-based approach

Multistage multiproduct chemical batch plants provide great flexibility but the task of scheduling them to meet product demands can be challenging. A typical scheduling problem involves the allocation of resources over time. A constraint-based approach to solve this kind of scheduling problems is considered. The essential feature of this approach is that it does not require elaborate mathematical formulae, but it requires a problem to be stated in terms of constraints. A general constraint model was created to represent a common class of chemical batch plants and a scheduling system was produced based on this model. A user can simply input the information of production requirements through a user interface and, if necessary, modify the constraints related to the specific problem and a viable schedule is created automatically.