RRP run, basic calculation for one itemThe planning engine matches the planned requirements against the planned receipts and identifies potential shortages. If the expected inventory level deviates from the inventory plan, LN generates rescheduling messages for existing orders, or generates new planned orders if necessary. In the following section, the steps of an RRP run are described. These steps are:
Alternative materials If the Use Up and Alternative Materials check box in the Implemented Software Components (tccom0100s000) session is selected, LN follows a modified algorithm. For more information, refer to Use-up materials and alternative materials in Enterprise Planning. 1. Determine the simulated time period LN carries out the simulation over a certain time period. The simulated time period is determined by the following factors:
For information about these factors, see Simulated time period (RRP run). 2. Consume demand forecast If no item master plan exists for a plan item, demand forecasts are recorded in the Special Demand by Item (cpdsp2100m000) session. Enterprise Planning performs forecast consumption to determine how much of the forecast has not yet been filled in by actual demand. This non-consumed forecast is taken into account during the planning process. 3. Determine the starting inventory LN determines the inventory at the start of the simulation by retrieving the current on-hand inventory, and adjusting this inventory for all planned inventory transactions until the start date of the simulation. 4. Place receipts and requirements on a time
axis LN places all existing requirements and scheduled receipts on a time axis for subsequent analysis. The following types of demand data are taken into account:
The following types of supply data are taken into account:
Note Before LN carries out a planning run, all previously created planned orders with Planned order status are removed. If you select the Remove Firm Planned Orders field in the Generate Order Planning (cprrp1210m000) session, LN also removes the previously created planned-orders with Firm Planned order status. The receipts and requirements are retrieved from:
5. Select next requirement Search for the next requirement. If a requirement can be found, subtract the required quantity from the inventory, and proceed with the next step. If there are no more requirements, go to step 10 (generate cancel messages). 6. Check the inventory If the inventory drops below the required inventory level, proceed with the next step (reschedule receipts), or else, return to step 5 (select next requirement). If an item has no item master plan, Enterprise Planning uses the safety stock to determine the required inventory level. You can define the safety stock in the Item - Ordering (tcibd2100m000) session. Here you can also specify a seasonal pattern for seasonal variations in the safety stock. If an item has an item master plan, the inventory plan in the Item Master Plan (cprmp2101m000) session is used. However, the inventory level in the first simulated period must be at least equal to the safety stock. 7. Generate rescheduling messages Search for the next receipt. If a receipt can be found:
LN generates two types of rescheduling messages:
For more information, see Exception Messages in Enterprise Planning. If the Only Reschedule Total Order Quantity check box in the Planning Parameters (cprpd0100m000) session is cleared, LN can also reschedule part of an order. You can let LN automatically process the rescheduling messages in the Process Exception Messages (cprao1220m000) session. For more information, see Order and order planning exception messages. Example
Requirements:
In this example there will be 3 rescheduling messages:
Note In the Exception Message Types by Planner (cprao1110m000) session, you can set a tolerance in days for rescheduling messages. For example, if you set a tolerance of one day for reschedule-out messages, the first rescheduling message in this example will not be generated. If there are no more receipts, proceed with the next step (transfer anonymous inventory). 8.Transfer anonymous inventory to project
inventory If the item is a project item that is derived from a standard item, LN can transfer inventory of the standard item to the inventory of the project item. See Project items in Enterprise Planning. 9. Generate planned order Generate a planned order and add the order quantity to the inventory. For more information, see To generate planned orders. Note A firm-planned order serves as a sort of additional time fence: LN does not generate planned orders before the last firm-planned order. If necessary, LN generates reschedule-in messages. However, you can override this rule by selecting the Planned Order before Firm/Actual check box in the Planning Parameters (cprpd0100m000) session. Return to step 5 (select next requirement). 10. Generate cancel messages Generate cancel messages for all scheduled receipts that are not yet selected. These receipts are unnecessary. 11. Update database LN stores the results of the simulation in the database. LN updates the data in the following sessions:
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