Page 260 - Orlicky's Material Requirements Planning

CHAPTER 12 Master Production Schedule 239

tor without any modification. If the consequences of a trial fit prove unattractive, the system
is restored to its previous condition simply by reversing and reprocessing the trial entries.
In some manufacturing businesses where it is feasible to match incoming customer
orders with the MPS or to incorporate them into it, trial fitting may be a regular proce-
dure. A trial-fit report then indicates which orders may be accepted with the customer’s
delivery-date request and which orders should be renegotiated for later delivery by a
specific number of periods. The MRP system determines this based on the availability of
component materials and lead time.

The Master Scheduler
An MPS, as mentioned earlier, may have two layers, the lower, more detailed of which
serves as input to the MRP system. With the advent of such a system, the position of mas-
ter scheduler in the production and inventory control department assumes special
importance.
The master scheduler (and his or her staff, if any) is responsible for creation and
maintenance of the lower-layer MPS. He or she converts product models into specific
end-item BOM numbers, divides monthly into weekly quantities, and forecasts product
options not specified in the (upper-layer) MPS or not forecast by marketing. He or she
keeps track of the use of safety stock provided at the MPS level, accounts for differences
between quantities of end items produced via the MPS and those consumed by the final
assembly schedule, and generally keeps the MPS up to date and valid.
An important function of the master scheduler is to evaluate problems of priority
integrity, as described earlier, that are brought to his or her attention by inventory plan-
ners who have traced a problem to the MPS by means of pegged requirements. He or she
determines which end-item lot should be changed and how, and he or she initiates a rec-
ommendation to management that such a change be authorized.
The position of master scheduler may be a new one, necessitated by the introduc-
tion of MRP. It constitutes an organizational link vital to closing the loop in the logistics
planning system. Other organizational aspects of operation under an MRP system will be
reviewed in the section that follows.

MANAGEMENT AND ORGANIZATIONAL ASPECTS
The MPS (or schedules, if there is more than one plant) documents the overall manufac-
turing program of a company. The development and administration of such a program,
viewed as a broad function, should be the joint responsibility of all four of the basic func-
tional divisions of a manufacturing enterprise, that is, marketing, manufacturing,
finance, and engineering. The first three of these are involved on a continuous basis,
whereas engineering enters the picture occasionally, when redesign or the introduction of
new products affects the manufacturing program.