I’m trying to understand why Master scheduling is creating a new planned purchase order, where I believe it should not, based on the fact that I have flagged ‘Use dynamic negative days = Yes’. Following is a very simple example:
My product is Min/Max controlled (min=10, max = 20). Fulfill minimum = Today’s date + Lead time
Today, March 23rd, there is no stock of the item. There is a sales demand of 7 pieces on March 29th
Lead time is 10 working; Purchase in multiple of 5; negative days is 5
After running master scheduling the system shows a planned order of 30pcs (requirement date April 10th, generating a future message given the lead time). This covers the sales demand, and the min. stock and replenishes to the maximum stock level (rouded up to nearest multiple). This is fine. Then the planned order is firmed.
Master scheduling then runs again. This creates a NEW planned order for 30 pcs. (There is an action message to reduce the firmed order from 30 to 10?). However, I expected NO new planned order as there is a firmed order due on April 10th that should still cover both the sales demand and min. stock, given that Use dynamic negative days = YES. By the way, if I change the negative days in the coverage group from 5 to 15 (more than lead time) I get the expected result… (i.e. no new planned order). I thought however that the dynamic negative days functionality should take care of this.
Any thoughts or perhaps a setup thing I might have overlooked.