ABSTRACT
In the last chapter, we introduced MRP as a production planning system appropriate for assembly environments in which dependent demand may be erratic. We argued that MRP is overkill for continuous process industries because of the relatively simple bills of materials and the closely linked production stages. Even in discrete parts manufacturing, when demand is high and relatively stable, MRP is not appropriate because it is specifically designed to look ahead and plan for periods of high or low demand. Likewise, MRP does not explicitly account for bottlenecks in production because it assumes infinite capacity. In this chapter, we discuss two production planning and scheduling systems, Just-in-Time (JIT) and Optimized Production Technology (OPT R©), that answer these limitations of MRP. We then introduce tools for decisions made at the level of the individual operator or machine. These are called short-range production scheduling tools and are particularly valuable for use in conjunction with OPT and in job shops.
