Abstract
Abstract Batch production is highly used in chemical process industries such as pharmaceuticals, cosmetics, food processing, etc. A few typical characteristics common in these industries are the long setup time and the long cleaning time. To minimize the cost and the frequency needed for the changeovers, the plants are operated in campaign mode. However, the products are often sold in small quantities with the fluctuating demands, the multi-purpose plants are preferred. While the multi-purpose plants gains the flexibility for the production planning, it becomes much more complex to decide how to run the plants, when and in what amount of different product should be made. In this paper, we study the planning problem in pharmaceutical industry and build a mathematical and decision model to characterize it. An empirical study is conducted to demonstrate the viability of the proposed model.