| Capacity CTP reservations |  |
| ERP LN calculates CTP reservations when a plan item's ATP is updated, or when an item master plan is updated. Capacity CTP reservation ERP LN generates a capacity CTP reservation in the following situation: The cumulative ATP of a plan item in a particular plan period becomes negative. You selected the Capacity CTP check box in the Items - Planning (cprpd1100m000) session for the plan item involved. ERP LN generates CTP reservations for the resources that are: Listed in the item's bill of critical capacities (BCC). Defined as critical in CTP. Note When component CTP reservations and/or capacity CTP reservations are made for a plan item, the expected additionally produced quantity of the item itself is stored as CTP Reservation Receipt. Calculation The capacity CTP reservation is computed as follows:
    CCR(t) = -NA(t) x	 CR(t)
CCR(t) | capacity CTP reservation
NA(t) | negative ATP
CR(t) | required capacity (from the bill of critical capacities)
The requirement date for the capacity CTP reservation is determined as follows:
    RD = PFD - LTO
RD | requirement date for the capacity CTP reservation
PFD | finish date of the originating plan period
LTO | lead-time offset (from the bill of critical capacities)
ERP LN records the capacity CTP reservation in the Resource Master Plan (cprmp3501m000) session in the plan period in which the requirement date falls. ERP LN subtracts the capacity CTP reservations from the resource's capacity CTP. You can view capacity CTP reservations and their origin in the Capacity CTP Reservations (cprmp5520m000) session. This session is accessible through the appropriate menu of the Item Master Plan (cprmp2101m000) session. Related topics Types of ATP and CTP checks Capacity CTP To compute capacity CTP CTP Checking Procedure Component CTP reservations |