Page 266 - Orlicky's Material Requirements Planning

C HAP TE R 13

More Than an

Inventory Control System

The early material requirements planning (MRP) systems were conceived and used as
replacements for their predecessor inventory control systems that were relatively primi-
tive and/or ineffective. In use of the new systems, the emphasis almost exclusively was
on order-release action. As the systems were further developed and refined, and as the
users gained experience in using them, it became apparent that an MRP system yields
information that can be of value for several purposes other than just inventory control.
Moreover, users discovered that with some minor additional programming, the system
could provide outputs in a number of functional categories and thus can serve as a plan-
ning system in areas well beyond the boundaries of traditional inventory control.
An MRP system that is properly designed, implemented, and used actually func-
tions on three separate levels:
1. It plans and controls inventories.
2. It plans open-order priorities.
3. It provides input to the capacity requirements planning system.

These are the three principal functions and principal uses of an MRP system.
Optionally, the system also can serve certain other functions briefly described below. The
three principal functions of the system will later be reviewed in more depth in separate
sections of this chapter.

USE OF SYSTEM OUTPUTS
An MRP system can provide a great number of outputs in a variety of formats at the
user’s option. It is not practical to list and describe all the specific outputs and formats
generated by MRP systems found in industry because outputs represent an aspect of the
system that lends itself to tailoring, individualization, and infinite modification. An MRP

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