RRP run, basic calculation for one item

The 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:

1. Determine the simulated time period.
2. Consume demand forecast.
3. Determine the starting inventory.
4. Place receipts and requirements on a time axis.
5. Select next requirement.
6. Check the inventory.
7. Generate rescheduling messages.
8. Transfer anonymous inventory to project inventory.
9. Generate planned orders.
10. Generate cancel messages.
11. Update database.

Alternative materials

If the 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:

• Start date and end date of the scenario.
• Time fence and order horizon.
• Net-change date.

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:

• Non-consumed demand forecast
• Actual sales orders
• Critical material requirements originating from master planning
• Dependent demand originating from planned orders
• Dependent demand originating from actual orders

The following types of supply data are taken into account:

• Planned orders with Firm Planned order status
• Planned orders with Confirmed order status
• Actual supply orders

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:

• The non-consumed demand forecast in the item master plan, or in the Special Demand by Item (cpdsp2100m000) session (if no item master plan exists).
• The critical material requirements in the Master Planning module.
• The planned inventory movements in the Order Planning module.
• The planned inventory transactions in the Inventory Planning module in Warehousing.
• The inventory transactions in the Inventory Reporting module in Warehousing.

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 Items - 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:

1. Add the received quantity to the inventory.
2. If necessary, generate a rescheduling message for this receipt.
3. Return to step 6 (check the inventory).

LN generates two types of rescheduling messages:

• Reschedule Out (move order to later date)
• Reschedule In (move order to earlier date)

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:

• Reschedule out from day 1 to day 2: 5 pcs
• Reschedule out from day 1 to day 3: 10 pcs
• Reschedule in from day 4 to day 3: 4 pcs

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:

• Planned Orders (cprrp1100m000)
• Planned Order - Inventory Movements (cprrp0511m000)
• Capacity Use by Planned Order (cprrp2100m000)
• Items - Planning (cprpd1100m000)