Continuous time model for short term scheduling of multi-product plant with parallel lines

In order to deal with batching problem in actual production, a mixed integer linear programming model of continuous time was proposed for short term scheduling of multi-product single-stage batch plant with parallel lines. Batching of the product demand and scheduling of the batches attained from the batching process could be accomplished simultaneously in the model. Meanwhile the sequence-dependent setup time was also handled in the model. Compared to the two-step method of batching as the first step and scheduling as the next step, the model has dramatically reduced the complexity of the model, and the solution of the model was more accurate and more practical. An example was given to illustrate the performance of the model.