Batch production time in a multi-stage system with material-handling consideration

In many production systems, batch jobs exist in the form of multiple, identical components. To facilitate movement between machines and simultaneous processing on several machines through several stages, the batch is usually split into unit loads or sub-lots. Such an operating mode improves resource utilization and batch completion time. Despite these benefits, published research dealing with the planning and control of unit-load-based manufacturing systems is still in the embryonic stage. In this paper, a model for the planning of production of a batch job through a multi-stage production system with multiple heterogeneous but functionally similar machines per stage is presented. The objective pursued is the minimization of batch manufacturing time. A dynamic programming based heuristic algorithm is developed for seeking a solution to the model. An example problem is described to demonstrate the procedure. The effect of changes in material-handling times, processing times, set-up times, and preparatory times on batch completion times were also investigated.