Simulating biotech manufacturing operations: issues and complexities

The Biotech industry is still an emerging application area for simulation techniques. This paper describes the hierarchical discrete event simulation efforts at Bayer Corporation´s Berkeley facility that manufactures second-generation recombinant DNA technology based drug, Kogenate-FS(R). The facility consists of multiple manufacturing areas housing state-of-the-art biotech processes. The main simulation issues included discretization of continuous activities, building appropriate level of detail in the models and conceptualizing biotech operations for simulation. Complexities arose from spread of manufacturing operations, sharing of common utilities, limited life-span of product and materials in-between stages coupled with limited storage capacities, regulatory constraints, industry-specific quality requirements and varying shift schedules, production capacities and batch sizes across stages. Even though the simulation efforts are not complete, the simulation models developed so far have saved Bayer substantial amount of money and have offered forward visibility for various strategic decisions over the last two years