A complex time based construction heuristic for batch scheduling problems in the chemical industry

In this paper we investigate a heuristic for batch processing problems occurring in the chemical industry, where the objective is to minimize the makespan. Usually, this kind of problem is solved using mixed-integer linear programs. However, due to the large number of binary variables good results within a reasonable computational time could only be obtained for small instances. We propose an iterative construction algorithm which alternates between construction and deconstruction phases. Moreover, we suggest diversification and intensification strategies in order to obtain good suboptimal solutions within moderate running times. Computational results show the power of this algorithm.