Hybrid approach of discrete event simulation integrated with location search algorithm in a cells assignment problem: a case study

This paper presents a case study describing a cell assignment problem in an assembly facility. These cells receive parts from external suppliers, and sort and sequence these parts to feed the final assembly line. Therefore, to each cell are associated important inbound and outbound flows generating hundreds of material handling equipment movements along the facility, impacting the traffic density and causing eventually safety issues in the plant. Following an important plant redesign, cells have been relocated, and the plant managers need to decide how to manage the new logistic flows. To that aim, a hybrid approach encompassing mathematical optimization and discrete event simulation (DES) is proposed. This approach allows us to reduce complexity by decomposing the design into two phases. The first phase deals with the problem of generating cell’s assignment alternatives by using a heuristic method to find good quality solutions. Then, a DES software is used to dynamically evaluate the performance of the solutions with respect to operational features such as traffic congestion and intensity. This second phase provides interesting managerial insights on the manufacturing system from both quantitative and qualitative aspects related to in-plant safety and traffic.