Flexible Lines with Setups: Analysis, Improvement, and Application
Cong Zhao, Jingshan Li, Ningjian Huang, John A. Horst
Setup times commonly exist in many flexible manufacturing lines to adjust tools and carry out safety and quality checks during product changeovers. In this paper, a Markov chain model is introduced to study flexible manufacturing lines with setups. An aggregation-based recursive procedure is introduced to evaluate system performance. The convergence of the procedure is proved analytically and the accuracy is justified numerically. Using such a method, the impact of setups is analyzed and the tradeoff between downtime and setup time reduction is investigated. Indicators are derived to identify the setup bottlenecks with respect to machine and product type, whose setup time reduction can lead to the largest improvement in line production rate. Finally, an application study at a furniture manufacturing plant is introduced.