Knowledge-based interactive scheduling of multiproduct batch plants

An interactive scheduling framework aimed at supporting the evolutionary modification of schedules by means of point-and-click mouse actions over a Gantt diagram is presented. The proposed framework relies on an explicit object-oriented representation of the schedule and supports, up to now, three categories of revision actions: operation-based (move, delete, swap, merge, etc.), order-based (insert, delete, modify) and resource-based (add/delete working shift) schedule modification functions. A rich underlying representation of the domain layer makes possible to keep track of different kinds of soft and hard constraints and prevents users from potential mistakes. Consequences of accepted revision actions are propagated and immediately depicted. During this constraint propagation phase an opportunistic approach is adopted to improve the schedule's quality.