Analyzing and Optimizing the Throughput of a Pharmaceutical Production Process

We describe a planning and scheduling problem arising from a pharmaceutical application. In a complex production process, individualized drugs are produced in a flow-shop like process with multiple dedicated batching machines at each process stage. Furthermore, due to errors jobs might recirculate to earlier stages and get re-processed. Motivated by the practical application, we investigate techniques for improving the performance of the process. First, we study some simple scheduling heuristics and evaluate their performance using simulations. Second, we show how the scheduling results can also be improved significantly by slightly increasing the number of machines at some crucial points.