Advanced Planning, Scheduling & APS worked example

Order Promise Date Buffer at 65% promise confidence level: a worked example

This worked example runs the order promise date buffer numbers for a tougher week than the baseline: 65% promise confidence level instead of the typical 90%. Estimate promise-date buffer exposure from open order quantity, time per order, confidence level, and fixed calendar buffer.

The inputs for this scenario

  • Open order quantity or load: 34 orders or hr (held at the documented default)
  • Promise time per order: 5.5 hr / order (held at the documented default)
  • Promise confidence level: 65 % (the input this scenario stresses; the baseline uses 90)
  • Fixed calendar buffer: 24 hr (held at the documented default)

Working through the calculation

  • The calculation starts from the formula this tool documents: Confidence-adjusted order load = open order load × promise time per order × promise confidence level.
  • Promise-date buffer requirement works out to 146 promise buffer hr at these inputs, and this is the headline figure for the scenario.
  • Promise time per order works out to 4.28 hr / order at these inputs.
  • Confidence-adjusted order load works out to 122 promise buffer hr at these inputs.
  • Fixed calendar buffer works out to 24 hr at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where promise confidence level sits at 90% and the headline result is 192 promise buffer hr, this scenario comes in 24.31% below the baseline at 146 promise buffer hr.
  • Use it when quoting a delivery date and you need a defensible lead-time cushion tied to current load and a target confidence. A result at this level usually justifies acting on the stressed input before touching anything else, because every other figure in the table is downstream of it.

Results at a glance

  • Promise-date buffer requirement: 146 promise buffer hr (headline result)
  • Promise time per order: 4.28 hr / order
  • Confidence-adjusted order load: 122 promise buffer hr
  • Fixed calendar buffer: 24 hr

Run it with your numbers

  • To rerun this with your own numbers, open the live Order Promise Date Buffer calculator, set promise confidence level to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.