What this procurement planner does
The planner works backward from a required-on-site date. For each material, it subtracts lead time, an item-specific delay, and a buffer to create a latest planned order date.
Calculation
Latest order date = required-on-site date − lead time − supplier delay − buffer. The result is a planning date, not a guaranteed supplier commitment.
If an item has no specific buffer entered, the global default buffer is used. The same approach applies to global supplier delay unless an item-specific delay is entered.
Worked example
If a material is required on 30 June, has a 45-day lead time, 5 days of supplier delay and a 7-day buffer, the modeled latest order date is 4 May.
Critical procurement items
An item becomes critical in this tool when its latest order date falls on or before the planning reference date. This does not mean the order is already late in a contractual sense; it means the modeled schedule has reached the reference point.
Why buffers should be visible
Combining all uncertainty into an unexplained lead time makes procurement risk difficult to review. Separate lead time, delay and buffer fields help teams see which assumption is driving the required order date.
Practical workflow
Use supplier-confirmed lead times where available, then revise the schedule when dates change. Long-lead materials can be reviewed independently of routine materials so procurement attention is directed where it matters.
Limitations
The planner does not know supplier calendars, holidays, shipping routes, purchase-order processing times or contract terms. Those details may need to be modeled separately.
Frequently asked questions
Can lead time be zero?
Yes. A zero lead time simply removes the lead-time component from the date calculation.
Does the tool know public holidays?
No. Calculations use calendar days without a holiday or working-day calendar.
Can I enter different buffers?
Yes. Every material has its own buffer field, with the global value used as the starting default.