Integral Logistics Management — Operations Management and Supply Chain Management Within and Across Companies

5.2.3 Master Scheduling — The Master Production Schedule (MPS)

Intended learning outcomes: Produce an overview on master scheduling and planning time fence. Present in detail the master production schedule (MPS) as a disaggregated version of the production plan. Explain the first task for establishing a master production schedule, which is the selection of the master schedule items.

Sales and operations planning works mainly with product families, that is, at an aggregate level of information. However, there will be a need for more specific information for individual products.

The corresponding planning process at the level of the individual product is called master scheduling[note 513].

The most important output of master scheduling is the master production schedule.

A master production schedule (MPS) is the disaggregated version of a production plan, expressed in specific products, configurations, quantities, and dates.

Figure shows an example of an MPS as derived from a production plan (shown here only for the first four months of a year).

Fig.        The MPS as a disaggregated version of the production plan (an example of a product family P with three different products, P1, P2, P3).

As the figure shows, the MPS is not only more detailed for individual products rather than product families, but it also yields much more detail for the time period for which the quantities are aggregated. It is thus a link between the production plan, which is relatively close to the sales plan, and the products the manufacturing department will actually build. The MPS is the input to all planning actions in the shorter term.

The planning time fence corresponds to the point in time denoted in the planning horizon of the master scheduling process that marks a boundary inside of which changes to the schedule may adversely affect customer deliveries, component schedules, capacity plans, and cost ([ASCM22]).[note 514].

Planned orders outside the planning time fence can be changed automati­cally by the planning logic of a software. Inside the time fence, the master scheduler, that is the person charged with the responsibility of managing the master schedule for select items, must deal with changes manually.

Establishing a master production schedule entails a number of tasks:

First task: Selection of the master schedule items, that is, the items managed by the master scheduler and not by the computer. Taking the example in Figure, if the difference between the products of the family P is due to three different variants of a assembly (namely, V1, V2, and V3) and if the delivery lead time allows assembling to customer order, then the best choice for the (customer) order penetration point (OPP) is the assembly level. The final products P1, P2, and P3 are then produced to customer order, according to the final assembly schedule (FAS) (see Section 7.1.5). If the usage quantity is 2 for each variant, then Figure shows the MPS corresponding to the production plan.

Fig.        The MPS on the level of assemblies V1, V2, and V3.

Continuation in next subsection (5.2.3b).

Course section 5.2: Subsections and their intended learning outcomes