Common due date

In this chapter we consider the scheduling problems with minimization of the earliness and tardiness costs, where all tasks should be completed at the same due date. Problems with minimization of the earliness and tardiness costs occur in just-in-time systems as we discuss in Section 1.1.4. Considering a common due date is relevant in the situation where several items constitute a single order, or they are delivered to an assembly line in which the components should all be ready at the same time to avoid storing inventories or delays of deliveries. Since this requirement cannot be fulfilled the scheduling objective is minimization of the earliness and tardiness costs.