Optimal scheduling for a multiproduct batch process with minimization of penalty on due date period

To make scheduling problems more realistic, we develop a new scheduling model with penalty functions for earliness and tardiness. Instead of a fixed due date, the scheduling problem is approached by taking the due date as a time period, which can handle flexible due dates and flexible customer requirements with penalty parameter modifications. We solve this optimization problem by the simulated annealing method and demonstrate its effectiveness with three examples.