Eric M. Malstrom

Evaluation of traditional work scheduling rules in a flexible manufacturing system with a physical simulator

Abstract This paper describes the use of a physical simulator to evaluate work scheduling rules in a flexible manufacturing system. An actual FMS was modeled using actual data. The performance of seven part selection rules and four machine center selection rules has been investigated. Six performance criteria have been used to evaluate the performance of all 28 decision rule combinations.

THREE DIMENSIONAL PALLETIZATION OF MIXED BOX SIZES

The pallet loading problem has historically been addressed in two-dimensions by attempting to maximize the pallet area utilized in each loading layer. This paper investigates a constrained version of three-dimensional pallet loading problem with mixed box sizes. This loading method allows many boxes of various sizes to be placed onto the same pallet. A restriction is placed on the number of boxes of each size that can be loaded. The modeling procedure presented converts the three-dimensional pallet loading problem into a standard mixed 0-1 integer programming model. The solution procedure for the formulated model is also described.

A Two-Dimensional Palletizing Procedure for Warehouse Loading Operations

Abstract A common warehouse/distribution problem is the unitization of pallet loads. A linear programming model has been developed to determine optimal stacking patterns on the basis of the dimensions of the boxes that constitute the load. The desired dimensions of the finished load may be user specified. No restriction is placed on the number of boxes of various types that may be loaded. The developed model is two-dimensional and assumes that all boxes have the same height.

A comparison of three computer assisted facilities design algorithms

Abstract This paper overviews and compares three computer assisted, facilities design algorithms. A new algorithm that utilizes computer graphics in conjunction with more cost minimization is compared with two traditional block layout algorithms. A comparison is made using actual data obtained from a midwestern manufacturer.

A simulation of single-level MRP lot sizing heuristics: an analysis of performance by rule

Abstract This paper presents the results of a large-scale computer simulation of 12 of the standard single-level, discrete demand lot sizing heuristics. The authors present the results in 3-D illustrations which depict the performance of these heuristics on 15 individual demand patterns. This information is prefaced by a brief review of the method used to perform the simulation. The performance of each of the 12 heuristics was evaluated for 51 sets of cost parameters for each of 15 different demand patterns. This has resulted in the analysis of 9180 combinations of heuristic, demand pattern, and cost parameters. The authors believe that this, by far, represents the largest digital simulation of single-level lot sizing rules completed to date. During the past two decades, a significant amount of research investigating the economics of lot sizing single-level discrete demand patterns has been conducted. However, many of the conclusions reached by individual research efforts on this subject have differed. At...

A design of personnel scheduling software for manufacturing

Abstract This paper describes Decision Support System (DSS) software to model personnel scheduling in a manufacturing environment. The DSS incorporates workload conversion, scheduling and costing functions to generate personnel requirements for a specified planning horizon in a conventional, MRP-driven manufacturing environment. This work was sponsored by the Material Handling Research Center, jointly located at the Georgia Institute of Technology and the University of Arkansas. The DSS consists of four modules. The Data Module accepts information from the master production schedule such as end-item demand and the bill of materials structure for each end item. Labor data such as worker categories, wages and overtime pay are also included here. This data is stored within an internal database. The Workload Conversion Module converts production demands for end items into worker capacity requirements for each work center by manipulating information from the Data Module considering worker categories, worker interchangability and the cost of each personnel schedule evaluated. The Cost Analysis Module assesses the cost of adding or reducing worker capacity and calculates the least cost personnel schedule that will satisfy the master production schedule. The Scheduling Module assigns workers to work centers by both worker category and time period. The scheduling heuristic considers worker interchangability, new hires, extra shifts, layoffs, overtime, weekend work and unexpected absences. Finally, the user is presented with all possible solutions and associated costs. The user may then select the set of solutions that he or she wishes to implement and the overall cost is calculated.

A decision support system for personnel scheduling in a manufacturing environment

Abstract A Decision Support System (DSS) is developed to support managers in the task of scheduling labor in the area of manufacturing. The DSS is designed to generate labor requirements by worker category and work center based on master production schedules. It is a PC-based, menu-driven program that generates a capacity plan based on data supplied by the user of the system.

A Three Dimensional Dynamic Palletizing Heuristic

This chapter extends earlier work on three dimensional palletization completed by the authors. Earlier work focused on the development of a mixed 0-1 integer programming model. While effective, the model proved to be computationally too complicated to permit its use in real time palletizing applications. This chapter describes the development of a three dimensional dynamic programming heuristic. The heuristic’s computational requirements lend themselves more readily to real time palletizing applications.

Required setup reductions in JIT driven MRP systems

Abstract Successful implementation of Just-in-time (JIT) production requires the frequent placement of small orders and the minimization of work-in-process (WIP) inventory levels. Successful JIT implementation requires the reduction of setup (order)costs to near zero levels. Recognizing that such reductions are not always attainable in practice, the authors have executed software that simulates the operation of Materials Requirements Planning (MRP) lot sizing methods. Using actual data, 9,800 simulation runs were performed. Our goal has been to determine the level of setup/order cost reduction to successfully implement JIT production ordering methods in an MRP environment.

Physical simulation of a three dimensional palletizing heuristic

Abstract This paper describes the effectiveness of a three-dimensional palletizing heuristic developed by the authors. It is shown that more boxes per unit time can be loaded with multi-pallet packing through reduction of non-productive movements of the robot to and from box storage areas. The use of the developed heuristic has been evaluated using a minalure robotic palletizing cell.