Multiple-Lot Lot Streaming in a Two-stage Assembly System

In this chapter, we address a lot streaming problem for a two-stage assembly system involving multiple lots with the objective of minimizing the makespan. Each lot consists of items of a unique product type. We designate this problem as a multiple-lot, two-stage assembly, lot streaming problem (ML-TSALSP) which combines two key decisions: lot splitting and lot sequencing. While the problem of scheduling in such a machine environment has been addressed in the literature, our problem is different because of the presence of the streaming of a lot over the stages. We derive some structural properties for this problem, and develop a branch-and-bound-based solution procedure that relies on effective lower bounds and dominance properties. Our computational investigation reveals the efficacy of the proposed branch-and-bound-based methodology for this problem.