To generate critical capacity requirements

When a production plan is generated, the critical resource capacity needed to carry out this production plan is recorded in the form of critical capacity requirements. In the the Resource Master Plan (cprmp3501m000) session, these requirements are displayed in the Capacity Used for Critical Capacity Requirements field.

Resource capacity is considered as critical capacity for the production of an item if the following conditions are met:

  • The resource appears as a critical work center in the item's bill of critical capacities (BCC) (see the Bill of Critical Capacities (cprpd3130m000) session).
  • The first date with capacity of the plan period in which the planned supply falls (or, if there is no such date, the first day of the plan period) has to fall between the effective date and the expiry date recorded for the critical capacity in the item's BCC.

As a rule, critical capacity requirements are generated when you update an item master plan (see To maintain an item master plan). When you use the Initialize, Roll, and Update Scenario (cprpd4200m000) session, however, you can disable the generation of requirements.

When a critical capacity requirement is planned, the duration of the production process is an important factor. Starting from the assumption that the supply of the end item is evenly distributed over a plan period, the capacity requirement is shifted back in the past using the lead-time offset and the lead time recorded in the BCC of the end item.

The start date for the critical capacity requirement is computed as the start date of the plan period minus the lead-time offset (in working days). The end date of the requirement is computed as follows:

Plan period end date - lead-time offset + lead time

The lead-time offset and the lead time are expressed in working days. The period comprised by the start date and the end date of the capacity requirement can overlap with more than one plan period. In that case, the required capacity is distributed over these plan periods in proportion to the available capacity (according to the resource calendar) in each plan period. For each combination of originating plan period and required plan period, a separate critical capacity requirement is recorded.

You can view the critical capacity requirements and their origin in the Critical Capacity Requirements (cprmp3560m000) session.