I’ve noticed when I run MS/MRP the lead time for Purchase Requisitions or Distribution Orders is calculated as Manufacturing Lead Time + Inspection Lead Time + External transport lead time + Transport lead time + Internal transport lead time when I have the primary supplier flag turned on, on the SFPP.

However if I use Planning Method B or C I’ve noticed the same logic is not applied. Instead the unlimited supply date on the inventory part is used, even if I have a primary supplier defined.

For MS/MRP this date is only used if I don’t define a primary supplier.

Is there a reason that the logic is different?