AN ALGORITHM FOR OPTIMAL SHIPMENTS WITH GIVEN FREQUENCIES

This article deals with the problem of minimizing the transportation a nd inventory cost associated with the shipment of several products fro m a source to a destination, when a finite set of shipping frequencies is available. A mixed-integer programming model-shown to be NP-hard-i s formulated for that problem. The computational complexity of some si milar models applied to different problems is also investigated. In pa rticular, whereas the capacitated plant location problem with operatio nal cost in product form is NP-hard, the simple plant location problem with the same characteristics can be solved in polynomial time. A bra nch-and-bound algorithm is finally worked out, and some computational results are presented. (C) 1996 John Wiley & Sons, Inc.