The MRP always breaks down the assembly requirements (e.g. from customer orders). If the sub-requirement (BoM of an assembly) is again an assembly, the system first checks whether this can be covered by stock or by planned inflow (= temporally stock reservation). If not, this is broken down further. For this, during the computation, the planned inflow is temporarily assigned to the planned outflow.
Example:
Sales order with Finished Product A
This product needs Semi-Finished Product B and B needs Material M
During the calculation of MRP Beas considers: A is required. If Order-related, Beas does not check the stock. You must produce this. B is stock-related. The system must produce it only if no stock is available. It checks the stock. If available, Beas reserves the requirement temporally for this Sales order.
If no Stock is available, the system simulates the production of B and creates a requirement for M.
Note:
B is Stock-related. Beas calculates this related to the requirement of the sales order. But it is used in view of a stock-related item. In the result you see the Sales order, which produced the requirement during the MRP calculation, but the result is always stock-related.
For stock-related items it is always better to set the correct view in MRP. You can do this with the setting “Accumulation” = Day/Week/Month
The reservations calculated during the MRP processing are made at a time when it is not yet known which sub-finished goods or material is actually required. At the time of MRP computation, the full balance calculation for each item is not yet known when processing a single document (work order, sales order etc.) Therefore, Beas uses the priorities described below for assigning the temporary reservation to different pegging originators.
| 1. | Minimum inventory [+] Example: Item A stock related, Stock 6 Pcs, Minimum 10 The system simulates a production order for 4 Pcs. This produces a requirement for 4 Pcs for Semi-Finished product B The requirement date for the Finished-Product (in this case A) is always today. |
| 2. | Existing production outflow (BOM) of work orders and planned orders [+] Order by Delivery Date ascending, Document Number Example: Work order existing for Finish Product “A”, 10 Pcs This has a Bill of Materials position “B”. If no stock is available, the system simulates a production order for Semi-Finished Product “B” and this produces the requirement for Material “M”. |
3. Customer orders, advance invoices, forecasts with setting "like customer order"
Order by Delivery Date ascending, Document Number
4. Transfer Requests
Order by Request Date ascending, Document Number
5. Forecasts (Default)
Order by Plan Date ascending, Document Number
The System first calculates all Minimum-Inventory requests, then Production order and so on. The system does not sort all requirements in one date line. The result can be a wrong order or temporally reservation for stock-related Semi-finished products. But in general, this is not a problem, because it is a stock related item.
The System does not only consider Stock. The following inflow is considered in order:
1. Remains from order multiples
2. Inventory
| 3. | Production receipts, ascending by date of receipt |
| 4. | Purchase receipts, purchase and production requests, ascending by date of receipt |
This behavior can be controlled with the respective options of an MRP calculation scenario:
The reservation criteria above are used by Beas in “real time” during the MRP calculation and should not be confused with a the fixed reservation that a user can do by linking stock quantities to a sales order line or the lines on a Work order BoM.
The temporary reservation determines whether sub-assemblies are broken down any further.
In case of working with fixed reservations, the reserved material is always firmly linked to a pegging and it may not be assigned to another pegging.
Item “A” has stock-related Sub-Assembly “B” with Material “M”
In this case, the first Sales (lowest Doc Number in SAP) order creates a requirement for “B” and the system covers this temporarily with stock.
Here are some issues that might arise in reading the MRP calculation results in relation with the time-line of a stock related sub-assembly:
Sales order 1: 1 Pcs, Delivery Date: 7th This produces different durations for the requirement of sub-assembly “B”, because you need more time for the production of Sales order “2”. The system calculates Sales order 1 and covers the stock for stock-related assembly "B".
In Balance List for B you see
and for Material
This means that when reading the MRP calculation results you might see the requirements of an item at a lower level of a product structure in a different order than at calculation time.
Note: If you use a precalculation inside a sales order, the production time for the order-related structure inside the precalculation is always the lead time of the item. |
Example Sales order with Calculation:
Sales order 1 with Item “A” with calculation, 100 Pcs, Delivery Date: March 10th
Sales order 2 with Item “A” without calculation, 100 Pcs, Delivery date: March 9th
This produce a requirement for item B:
Sales order 1: March 10th (no calculated production time)
Sales order 2: March 5th
In MRP you see first Sales order 2 (sorted by requirement date), but the system calculate first Sales order 1 and use the existing stock for B for this sales order.
Note: Item B is stock-related. It is not possible to see order related result in stock-related items.
Note:
All production receipts are taken into consideration, regardless of the warehouse they are posted to. Warehouse settings defined in the MRP calculation scenarios > Warehouse are not considered here.
The temporary reservation calculated by MRP can be displayed after the computation in Order recommendation report > Origin.
In this list all temporary links are displayed in a structure view. See origin of requirement structure.
Consider inflow in future
If the date of delivery would be taken into consideration, the following problem could occur:
Assembly “A” contains assembly “B” with material M1.
Sales Order: assembly “A” on May 5th
Requirement of assembly “B” on May 3rd and material M1 on May 1st.
Work order is created for May 3rd, material is ordered for May 1st.
All requirements are covered.
The customer asks for a delivery one day earlier, on May 4th:
If the requirement coverage calculation would consider the delivery date, the work order would no longer cover the requirement.
In effect, assembly “B” would be broken down, although the balance is 0. From the work order and the sales order a requirement would arise for material M1 - and thus it would be ordered twice.
To prevent this, the delivery date is not considered.
The delivery date is taken into account, but it may be in the future. This is set up in Configuration wizard > Detail > Breakdown replenishment > “Consideration of future receipt”.
The delivery date is not taken into account - except for point 1 - since otherwise there would be a risk that the sub-material is dispatched twice. For this reason, Configuration wizard > Detail > Breakdown replenishment > “Consideration of future receipt” parameter is set to 99 days.
If “Consider inflow in future” is activated, the system covers the work order, which is 1 day in the future and you need in the example the Material "M" only.
Example:
This item is a stock-related sub assembly. The order in this list is by Date of requirement.
Before the system checks which material is needed for the assembly, it checks if stock is available for this assembly.
If yes, Beas reserves the stock for this assembly and you do not need to produce it. The system does not check the required material.
The temporal reservation uses the defined priority: Minimum Stock, Production order, Sales order and so on.
What this means: Beas reserves the material for the work order (line 3) and not for the sales order (line 1 or line 2).
Right mouse click on line 3 - Origin you can see the defined reserved quantity.
Filter Only shortage
This filter shows all items that need to be ordered or produced, or for which the planned inflow is too late.
In this case, assembly “B” would be shown as shortage, as the balance for 4th May is negative.
The inflow to be used can be specified in MRP wizard > Detail > Breakdown of resources.