An Engineered Approach to Optimal Scheduling

Options for assignment of the equipment The assignment of the units to the processing steps is fixed with respect to the stages of the plant but variable with respect to particular units within the stages (e.g., the reactors of the polymerization stage). 

Connectivity The connectivity of the plant can be considered as full with respect to the given recipes as it does not constitute additional constraints. 

Batch size The batch sizes in the preparation stage and in the polymerization stage are variable as batches may be split in the preparation stage and mixed in the polymerization stage. However, the concept of batches does not apply in the finishing stage. 

Demand patterns Multiple product demands appear which are specified by their amounts and their due dates. 

Changeovers No changeovers appear in the preparation stage and in the polymerization stage. The start-ups and shut-downs of the finishing lines are changeovers with certain set-up times which cause costs (see below). 

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