The Basic Concept: Negative Days
Negative days represent the number of days a delivery can be late before the system needs to create a new replenishment order. During this period, the item's inventory level is allowed to go negative. Intra-Cloud Dynamics
In practice, it's the answer to the question: "how long am I willing to wait before ordering again, knowing I already have something inbound?"
Set negative days to zero and the system becomes very reactive — it tends to create new planned orders even when existing supply is already close to the requirement date. Set them too high and you risk accepting delays your customer won't tolerate.
CASE 1
The Setup
| Parameter | Value |
|---|---|
| PO receipt date | 09/06/2026 |
| PO quantity | 5 kg |
| Requirement date | 04/06/2026 |
| Requirement quantity | 3 kg |
| Item lead time | assume 5 days (so earliest replenishment = today 04/06 + 5 = 09/06) |
| Negative days | 0 |
D365FO result CASE 1
The two transactions are settled together.
CASE 2
The Setup
| Parameter | Value |
|---|---|
| PO receipt date | 09/06/2026 |
| PO quantity | 5 kg |
| Requirement date | 04/06/2026 |
| Requirement quantity | 3 kg |
| Item lead time | assume 4 days (so earliest replenishment = today 04/06 + 5 = 09/06) |
| Negative days | 0 |
D365FO result CASE2
New planned order created and suggestion to delete the one already firmed.
CASE 3
The Setup
| Parameter | Value |
|---|---|
| PO receipt date | 09/06/2026 |
| PO quantity | 5 kg |
| Requirement date | 04/06/2026 |
| Requirement quantity | 3 kg |
| Item lead time | assume 4 days (so earliest replenishment = today 04/06 + 5 = 09/06) |
| Negative days | 1 |
D365FO result CASE3
