Page 280 - Orlicky's Material Requirements Planning

C HAP TE R 14

System Effectiveness:

A Function of Design and Use

The design, or architecture, of material requirements planning (MRP) systems has by now
been standardized, and it is embodied in the application software that computer manufac-
turers offer to their customers. The MRP program packages are popular in the manufac-
turing industry, and in fact, most of the existing MRP systems use standard software; only
a small minority of these systems has been designed and programmed by users.
This is not to say that a large number of installed MRP systems are identical—there
probably are not two exactly alike. This stems from the fact that the user of standard soft-
ware has considerable freedom in how he or she constructs his or her particular system
by configuring the modules (functions) making up the package, what decisions he or she
makes about certain parameters of use, and whether he or she uses so-called program
exits to supply his or her own programming of procedures not provided in the package.
The effectiveness of the system that results depends, in part, on the decisions the user
made at the time of system construction. However, no matter how well the system may
have been designed technically, its true effectiveness also depends on how well it is being
used. Both these considerations will be addressed in this chapter.

CRITICAL SYSTEM DESIGN FEATURES
The three principal functions that an MRP system can provide—at the user’s option—
were reviewed in Chapter 13 and for purposes of design can be summarized in the fol-
lowing checklist of objectives:

1. Inventory:
■ Order the right part.
■ Order in the right quantity.
■ Order at the right time.

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