Just in Time Manufacturing: A Migration from Materials Requirements Planning

Manufacturing planning and control systems play an important role in an organization\u27s effectiveness. Over the past twenty to thirty years, U.S. manufacturing companies have faced increasing competition for market share from Japanese and other Pacific rim countries. This thesis will investigate the evolutionary path followed by manufacturing companies that have implemented various manufacturing planning and control systems. Specifically, Materials Requirements Planning (MRP) and Just In Time (JIT) production will be analyzed. MRP is a means of convening demand for the final product into a requirements schedule for the various components comprising that product. The JIT philosophy calls for continuously improving all parts of the manufacturing function, such as, plant layout and design, organizational structures, total quality management, and vendor relationships. Why is this an area of interest to American manufacturers? MRP is an American development, and many American manufacturers have implemented MRP systems since the late 1950\u27s. However, recent emphasis on time-based competition within manufacturing organizations has caused many of those companies to supplement their MRP systems with a JIT system. In other words, a Jff system has supplanted the MRP system. MRP and JIT are not competing approaches to planning and controlling manufacturing operations; each offers benefits not offered by the other alone. This fact suggests that the most ideal manufacturing planning and control system will probably embody elements of both MRP and JIT