Design and Evaluation of Wood Processing Facilities Using Object-Oriented Simulation

Managers of hardwood processing facilities need timely information on which to base important decisions such as when to add costly equipment or how to improve profitability subject to time-varying demands. The overall purpose of this paper is to introduce a tool that can effectively provide such timely information. A simulation/animation modeling procedure is described for hardwood products manufacturing systems. Object-oriented simulation modeling techniques are used to assist in identifying and solving problems. Animation is used to reduce the time for model development and for communication purposes such as illustrating “how” and “why” a given solution can be effective. The application and utility of the simulation/animation tool is illustrated using a furniture rough mill system characteristic of the eastern region of the United States. INTRODUCTION The wood household furniture, cabinet, and millwork industries employ over 385,000 people, have a total annual payroll exceeding $6.6 billion, and generate over $15 billion annually in value-added manufacturing (6). However, this industry faces serious economic and technical problems that are limiting its profitability and growth. The increasing cost of high-quality hardwood 1The authors are: D. E. Kline, Assistant Professor, Department of Wood Science and Forest Products, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061 and P. A. Araman, Project Leader, Primary Hardwood Processing and Products, Southeastern Forest Experiment Station, Brooks Forest Products Center, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061. This research was sponsored by USDA/FS through Cooperative Research Agreement No. 29-474, and the Virginia Agricultural Experiment Station. timber resources along with labor-intensive manufacturing methods have pushed manufacturing costs close to unprofitable levels. Furthermore, competitive pressures from foreign companies are threatening these industries. If the industry is to survive and grow under such pressures, it must be able to recognize and solve some fundamental. manufacturing problems. TO address some of these problems, research has focused on developing better processing equipment technology. Innovative technologies such as computer vision, robotics, and computer-integrated manufacturing which have been successfully employed in other manufacturing industries, have been proposed for modernizing furniture manufacturing facilities (8, 9, 10, 11). Although modern equipment is very important to a wood products manufacturing plant of the future, improving equipment technology alone is not enough to address all of the industry’s problems. A more complete solution to the problems of the wood furniture, cabinet, and millwork industries involves determining a combination of technology and management that is best for the overall manufacturing system. Studying only one component of such a broad system in isolation from other components may not produce the best overall results. Computer simulation is an effective operations research tool for analyzing whole manufacturing systems. Using computer simulation, alternate processing technologies, management techniques, and control strategies can be thoroughly studied before their costly introduction into a real manufacturing system. Several systems simulation models have been developed to assist in designing, evaluating, and managing hardwood lumber and furniture manufacturing systems. Some of the models have proven very successful in addressing specific questions within given forest products operations (3, 14).