The production plan represents a firm’s aggregate measure of manufacturing output. Once this plan is made, it is the responsibility of marketing to sell it and production to implement it. To do so requires a desegregation of the production plan into individual products. The master production schedule (MPS) is a statement of how many finished items are to be produced. Typically the master schedule is developed for weekly time periods over 6-12 months horizon.
Master scheduling is generally a complex problem, especially for products with large number of operations For example, in Dow Corning there are 12 MPS; who are responsible for scheduling 400 packed products over a 26-week time horizon. In process industries with only a few different operations, master production scheduling is somewhat easier.
Using the Master Schedule: Master scheduling can be a complicated process. Let us summarize some of the observations.
- First, the master production schedule should relate to the aggregate products.
- Second, rough-cut capacity planning assists the master scheduler in developing a feasible schedule by determining potential production bottlenecks. Often, the master scheduled must be revised several times until it is feasible.
- Third, other ways of evaluating a master production schedule include the and cost of setups or product changeovers and short-term inventory fluctuations.
The master schedule is important, since it forms the basis for future production planning activities. Therefore, it must be adaptive to changes in the environment. Seldom will forecasted demands be realized or production plans be adhered to perfectly. As each week passes, operations managers must compare scheduled production with actual results. This may result in changes to the MPS-master scheduling is a full time job! Too many changes, however, indicate that master scheduling is not being performed correctly and can result in poor productivity and low levels of customer service.