Thom J. Hodgson

A Combined Approach to the Pallet Loading Problem

Abstract In this paper the two-dimensional pallet loading problem is considered: that is, the problem of loading a rectangular pallet of size L by W, drawing from a set of n rectangular boxes. The objective is to maximize the area covered on the pallet by the boxes loaded. The problem is approached using a combination of dynamic programming and heuristics. The structured solutions resulting from the application of the dynamic program have two serendipitous characteristics: any item may be placed on the periphery of the pallet for easy access, and some control may be retained over the center of gravity of the pallet. Computational results are given.

Production Lot Sizing with Material-Handling Cost Considerations

Abstract The determination of production lot sizes and the assignment of storage space in a warehouse for the produced items are usually treated as two separate problems, the former providing input (space needed) to the latter. In this paper, we treat the decision problems as one with the objective of minimizing total setup, inventory carrying, and warehouse material-handling costs. We treat the minimum material-handling cost as a continuous function of the lot sizes and develop an algorithm for finding locally optimal solutions of the derived optimization problem. Computational experience is provided and a special case of the problem is shown to be equivalent to a single-processor scheduling problem.

An N-Product, Multi-Machine, Lotsize Scheduling Model

Abstract In this paper we consider an N-product, multi-machine, lotsize-scheduling problem that was originally encountered in a large automotive metal stamping facility. It is shown that the natural constraints of the real-life problem provide a special structure which allows an efficient formulation of the problem as a 0–1 integer program. An implicit enumeration algorithm for obtaining numerical solutions is presented. Computational experience shows that the algorithm is quite efficient when the number of products does not exceed ten or eleven. In the automotive metal stamping facility, that number is rarely exceeded; therefore, it is possible to employ the model as one of the basic tools used by a team responsible for the development of a production planning system.

A Naval Air Rework Facility Scheduling Problem

In the following paper we describe an independent job shop production sub-system within the Jacksonville Naval Air Rework Facility, Jacksonville, Florida. The various job flows within the shop are identified. The mechanisms controlling job flows are quantified. The controllable costs of operating the shop are identified and the scope of control open to management is discussed. Finding a method of control for the system is left as a challenge for the reader.