Page 185 - Orlicky's Material Requirements Planning

164 PART 2 Concepts

sen. At this point in the discussion, however, we need not be concerned with the distinc-
tion. Thus far we have been dealing only with the status data (the most important seg-
ment of the record), and there are a few more aspects of this segment to be reviewed
before describing the header and subsidiary segments.

Time-Phased Record Format

The most compact format of recording and displaying time-phased inventory status data
is the one introduced in Chapter 7 and used in several previous examples. It consists of
four rows of time buckets representing the following:
1. Gross requirements
2. Scheduled receipts (open orders)
3. On hand (current and projected by period)
4. Planned-order releases
This format accommodates all the information that is essential for the proper manip-
ulation of status data and for operation of the MRP system. The four rows of buckets
define inventory status in summary form, and the format contains implicit information
that can be inferred from the data that are displayed directly. This is the standard format
favored by many MRP system users, and it is the format normally used for purposes of
communication and instruction.
At the option of a given user, however, the format can be expanded in such a way
as to provide more detail and/or to state more of the information explicitly. Figure 9-1
shows both the compact and expanded formats based on the same status data. The exam-
ple illustrates the possibilities of expansion rather than the format of an actual record. In
practice, the expansion is usually limited to adding separate net requirements and/or
planned-order receipt buckets.

Optional Fields

In addition to what is shown in Figure 9-1, the status segment of the inventory-item
record may include a field labeled “Allocated on hand.” Allocation was discussed in
Chapter 5. The quantity allocated indicates the quantity of the item earmarked for a par-
ent order (or orders) that has been released but for which the material requisition has not
yet been filled.
The allocated parts “belong” to the respective parent orders, and they are still phys-
ically on hand in the stockroom only because of the time gap between order release (by
the inventory planner) and the filling (by the stockroom) of the supporting requisition for
component materials. Where a single allocation field in each inventory record is being
maintained, it is understood that parent orders normally will be released during the peri-
od for which the release is planned and not before. Also, it is assumed that all the com-
ponent items are required at the time the parent order is released. Both these conditions