Optimization for material flow in production systems based on lot-transfer between workstations

Material flow with lot-transfer between processes in mass and batch production system is analyzed. New formulations are developed which include deciding the optimal output lot size, production batch-size and transport lot size in the production systems. Based on the characteristics of multi-variety and batch-and-turn manufacturing, the production-overlap factor is presented and is used to modify the traditional resource restriction conditions. For multiple resource restrictions, the restrictive factor of the key resource is identified and used to modify the batch-size. Compared with traditional ones, the algorithms for optimizing material flow developed in this paper are simpler, more effective and appear suitable for real production systems.