Generating critical material requirements
When a production plan is generated, the critical components needed to carry out this production plan are recorded as critical material requirements. In the Item Master Plan (cprmp2101m000) session, these requirements are visible as dependent material demand.
A component is considered a critical material for the production of an item if the following conditions are met:
- The component appears in the item's bill of critical materials (BCM) (see the Planning Bill of Critical Material (cprpd3120m000) session).
- The first date with capacity of the plan period in which the planned supply falls (or, no such date exists, the first day of the plan period), must fall between the effective date and the expiry date recorded for the critical component in the item's BCM.
As a rule, critical material requirements are generated when you update an item master plan (refer to the topic To maintain an item master plan. (When you use the Initialize, Roll, and Update Scenario (cprpd4200m000) session, you can disable the generation of requirements.)
Because the production process takes time, the planning of a critical material requirement must fall before the planned supply of the end item. Assuming that the supply of end item is evenly distributed over the plan period, the material requirement is shifted back in the past with the lead-time offset recorded in the bill of critical materials of the end item.
Offsetting logic BCM
LN takes into account the parent / component relation when it calculates dependent demand for critical items. As a result, LN plans a multiple of the bill of critical materials (BCM) quantity in each plan period. The advantage is that you do not have to wait until the production plan of all the periods over which the dependent demand is spread, is executed.
The offsetting process to plan critical components is as follows:
- Create a production plan for the parent item.
- Offset the lead time of the parent item to the plan periods, and divide the amount of the forecasted demand over the available plan periods.
- Round the forecasted demand to the parent unit set according to the unit set that you defined for the parent item in the Items (tcibd0501m000) session.
- Multiply each BCM quantity of critical components of the parent item.
- Round the (critical) dependent demand according to the component unit set.
- The start date for the critical material requirement is computed as the start date of the plan period minus the lead-time offset (in working days).
- Likewise, the end date of the requirement is computed as the end date of the plan period minus the lead-time offset (in working days).
- The period comprised by the start date and the end date of the material requirement can overlap with more than one plan period. In that case, the required quantity is distributed over these plan periods in proportion to the available capacity (according to the company calendar) in each plan period.
- For each combination of originating plan period and required plan period, a separate critical material requirement is recorded.
You can view the critical material requirements in the Critical Material Requirements (cprmp2505m000) session. The origin of critical material requirements is displayed in the Critical Material Requirements (cprmp2505m000) session.