Planning Material Handling Vehicle Routes for Internal Just-In-Time Operations

The problem of supplying JIT assembly workstations from a central depot with a goal of minimizing inventory and vehicle requirements is the focus of this paper. To minimize work-in-process inventory, the quantity of component parts delivered to each workstation must be just enough to satisfy production until the next delivery of components. To minimize vehicle requirements, there should be no vehicle idle time. The problem is modeled as a vehicle routing problem with a nonlinear capacity constraint. A heuristic solution procedure is outlined and a relaxed formulation is given to provide a lower bound on the number of vehicles required.