Hot rolling steel tube batch scheduling with earliness/tardiness penalties

Abstrcat The hot rolling steel tube batch scheduling problem with earliness/tardiness penalties as a mixed integer non-linear programming model is discussed. The optimal batching method under given order sequencing is presented and proved. Based on the optimal batching method, the original problem is changed into an easier sequencing problem. A model for the new problem is then developed and a genetic algorithm is designed. The computation results show the effectiveness of the model and algorithm.