An MILP Approach for Short-term Scheduling of Batch Operations

In this paper, we address the short-term scheduling of multipurpose batch plants, a challenging problem that has received growing attention in the past few years. We present a new mixed integer linear programming (MILP) framework based on the state-task network (STN), which employs a multi-grid continuous-time approach. Compared to other formulations in the literature, the proposed model leads to smaller and simpler mathematical models with strong LP-relaxations, which is reflected in the ability to find the optimal solutions in shorter CPU times. We demonstrate the performance of our model with a complex and comprehensive case study from the literature.