A Comparative Study to Investigate the Effect of the Number of Sub-Lots in a Multi-Stage Multi-Product Flowshop Lot-Streaming Problem with Consistent Sub-lot sizes: A Case Study

摘要

Lot-streaming in flowshop models is intensely studied and numerous results are obtained and reported in the literature. The maximum number of sub-lots is relaxed in many of these published research works. However, in real-life situations, limitation on the number and capacity of material handling facilities or technical considerations may constrain decision makers to plan for moving too many of sub-lots between machines on the shop floor. To tackle this problem, some researchers have put an upper bound on the number of sub-lots and/or on their size. In this paper, we aim at investigating the impact of a maximum number of sub-lots on makespan. To this goal, a comparative study is conducted to find out if with the assumption of consistent-sized sub-lots, equal and unequal sub-lot sizes affect makespan. Then using discrete-event simulation and a generic MIP model, a relatively good policy is obtained and applied to a case study to minimize the makespan.