Application of discrete event simulation in production scheduling

The article describes the application of discrete event simulation in a process industry (coffee manufacturing) as a daily production scheduling tool. A large number of end products (around 300), sporadic demand, and limited shelf life of coffee (90 days) make it difficult to generate feasible production schedules manually. To solve this problem, an integrated system was developed incorporating discrete event simulation methodology into the scheduling process. The integrated system is comprised of two components: a scheduling program and a simulation model. The scheduling program is used to generate daily schedules for roasting, grinding, and packing coffee. The simulation model uses the generated schedules to simulate the production of coffee and regenerates a modified production schedule. Each of the components are described in detail, evaluated in terms of performance factors, and validated with a set of real production data. Although the article focuses on a specific system, we share our experiences and intuitions gained and encourage other process industries to develop simulation based scheduling tools