Dynamic scheduling to minimize lost sales subject to set-up costs

We consider scheduling a shared server in a two class make to stock closed queueing net work We include server switching costs and lost sales costs equivalently server starvation penalties for lost jobs If the switching costs are zero the optimal policy has a monotonic threshold type of switching curve provided that the service times are identical For completely symmetric systems without set ups it is optimal to serve the longer queue Using simple an alytical models as approximations we derive a heuristic scheduling policy Numerical results demonstrate the e ectiveness of our heuristic which is typically within of optimal We also develop and test a heuristic policy for a model in which the shared resource is part of a series network under a CONWIP release policy