SAP MRP Order Quantity Calculator with Rounding Value
Planners are often surprised that MRP proposes 2,000 pieces when the shortage is 1,730. The difference comes from assembly scrap, minimum lot size, rounding value and maximum lot size in the material master. This tool shows each step and the excess it creates.
Your numbers
Shortage found by the MRP run in the planning bucket.
Field Assembly scrap (%) in MRP 4, mainly for components.
Order is rounded up to a multiple of this value, such as a pallet or box size.
Larger proposals are split into several orders.
Your results
Simplified: SAP applies lot sizing, minimum, maximum and rounding in a defined sequence that also depends on rounding profiles and the lot size procedure. Use this to estimate, then confirm with an MRP run in a test client.
Proposed quantity vs net requirement
Sweeps Net requirement from 0 to 5000, holding your other inputs fixed.
MRP excess stock review
Optional: we can compare MRP proposals with demand in an export and list the materials where rounding and minimums create the most excess.
Optional. The tool and every export work without this. No spam.
How to use the calculator
Enter the net requirement MRP found, the assembly scrap percentage, the minimum and maximum lot sizes and the rounding value. The calculator increases the requirement for scrap, rounds it up to a multiple of the rounding value, applies the minimum lot size and tells you how many proposals result if the maximum lot size forces splitting. The chart sweeps the net requirement so you can see the staircase created by the rounding value.
- Find the fields in MRP 1 and MRP 4 views
- Match the rounding value to supplier pack size
- Check whether a rounding profile overrides it
Method and order of operations
Assembly scrap inflates the requirement so that the usable quantity still covers demand: gross equals net divided by one minus the scrap rate. Rounding up to a multiple takes the ceiling of gross divided by the rounding value, times the rounding value. The minimum lot size sets a floor, and the maximum lot size splits larger quantities into several orders. A requirement of 1,730 with 3 percent scrap becomes about 1,784, which rounds up to 2,000 with a rounding value of 250.
Reading the output
Excess is the stock you create on purpose to satisfy pack sizes and minimums. Small excess on cheap items is fine. Large excess on expensive items points to a rounding value or minimum lot that is too large for the demand pattern, or a case for negotiating smaller pack sizes. If many proposals appear because of the maximum lot size, check whether that limit still reflects equipment or transport capacity.
Common mistakes
A common mistake is setting a rounding value equal to the minimum lot, which hides real demand signals. Another is entering assembly scrap on finished goods, where it inflates dependent requirements for no reason. Also remember that rounding values in the info record or purchasing view can differ from the plant level setting.
- Keep one source of truth for pack sizes
- Review scrap rates against actual yield
- Do not apply scrap twice in BOM and material master
Frequently Asked Questions
Where is the rounding value maintained?
In the MRP 1 view of the material master as Rounding value (MARC-BSTRF), and optionally through a rounding profile. The info record can also hold a rounding setting for purchasing.
What is assembly scrap in SAP MRP?
A percentage maintained in the MRP 4 view for components. MRP increases the dependent requirement of the component so that after expected loss in assembly the right quantity is available.
How does maximum lot size work?
If the calculated lot is larger than the maximum, MRP splits it into several procurement proposals no larger than the maximum, with the same availability date or staggered by the lot size settings.
Does rounding apply to all lot size procedures?
Rounding value applies with most dynamic procedures. For fixed lot size, the fixed quantity is already the unit of procurement, and multiple lots are generated until the requirement is covered.
Netray can compare MRP proposals with real requirements across your materials and list where rounding and minimums create the most excess stock.
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