Page 192 - Orlicky's Material Requirements Planning

CHAPTER 9 System Records and Files 171

Transaction Effects

The designer of an inventory control system must decide how many different types of
transaction are to be recognized, how they are to be coded, and how they are to be
processed by the system. The choices are virtually unlimited, and dozens of transaction
types may be recognized in a given system. The range and treatment of both transactions
and pseudotransactions will be reviewed later in this section. While there is no limit to
the number of different transaction types that may be used, there is a limited number of
effects that these transactions can have on inventory status. Thus a number of different
transaction types will affect inventory status the same way.
For example, a stock receipt of an overrun, a customer return, and an inventory
adjustment up (the result of a physical count) will increase the quantity on hand and
reduce net requirements. The different effects that various transactions can have on a
time-phased inventory record are as follows:

External transactions affecting one record:
1. Change quantity of gross requirements.
■ Secondary effect: Recompute projected on hand; recompute planned-order
releases.
2. Change quantity of scheduled receipt.
■ Secondary effect: Recompute projected on hand; recompute planned-order
releases.
3. Reduce scheduled receipt and increase quantity on hand.
4. Change quantity on hand.
■ Recompute projected on hand; recompute planned-order releases.
5. Reduce quantity on hand and reduce gross requirements.
6. Reduce quantity on hand and reduce quantity allocated.

External transactions affecting multiple records:
7. Change quantity of planned-order release (parent record) and change quantity
of gross requirements (component records).
■ Secondary effect: Recompute projected on-hand and planned-order release in
component records.
8. Reduce quantity of planned-order release and increase scheduled receipts
(parent records); reduce gross requirements and increase quantity allocated
(component records).
■ Secondary effect: Recompute projected on-hand in parent record.
9. Increase quantity of planned-order release and reduce scheduled receipts
(parent record); increase gross requirements and reduce quantity allocated
(component records).