Lot streaming with variable sublots: an integer programming formulation

This paper deals with the question of how to split a given lot into sublots so as to allow their overlapping production in a flow shop environment. The size of each sublot may vary over the stages. We consider an arbitrary number of stages and assume sublot availability, that is, only completed sublots are allowed to be transferred to the next stage. A mixed integer programming formulation is presented, which enables us to find optimal solutions for medium sized instances. The model is extended further to deal with different settings and objectives. Computational results confirm that the exploitation of variable sublots is advantageous and may lead to a significant increase in productivity.