Examples: Cumulative Lead Time Calculations 
The following example explains how to calculate cumulative lead time for a parent item in a bill of materials (BOM) structure.
Standard/Special Production Order for a Production BOM
The following list presents a production BOM structure:
Parent item PBOM1 (Production BOM; Lead Time: 1 Day)
C1 (Lead Time: 1 Day)
ABOM2 (Assembly BOM; Lead Time: 2 Days)
C4 (Lead Time: 4 Days)
P1 (Phantom Item, Lead Time: 1 Day)
C5 (Lead Time: 5 Days)
PBOM3 (Production BOM, Lead Time: 3 Days)
C6 (Lead Time: 6 Days)
SBOM4 (Sales BOM, Lead Time: 4 Days)
C7 (Lead Time: 7 Days)
The MRP does not consider the lead time for assembly BOMs, sales BOMs, and phantom items. Therefore, in this example, the lead time for ABOM2, SBOM1, and P1 are not included in the calculations.
The table below demonstrates how the lead time is calculated based on the BOM structure:
July 1 |
July 2 |
July 3 |
July 4 |
July 5 |
July 6 |
July 7 |
July 8 |
July 9 |
July 10 |
July 11 |
|
|---|---|---|---|---|---|---|---|---|---|---|---|
PBOM1 |
OR |
Requirement from sales order |
|||||||||
C1 |
OR |
||||||||||
ABOM2 |
|||||||||||
C4 |
OR |
||||||||||
P1 |
|||||||||||
C5 |
OR |
||||||||||
PBOM3 |
OR |
||||||||||
C6 |
OR |
||||||||||
SBOM4 |
|||||||||||
C7 |
OR |
Therefore, the cumulative lead time for PBOM1 is 10 days, as you can observe from the table above, from July 1 to July 10.