ERP & MRP Planning worked example

Available to Promise with available supply before new order of 900 units: a worked example

Suppose available supply before new order falls to 900 units. This page works the full calculation at that level so you can see exactly which result moves and by how much. Estimate available-to-promise quantity after firm sales allocations, safety stock, and quality holds.

The inputs for this scenario

  • Available supply before new order: 900 units (the input this scenario stresses; the baseline uses 1,800)
  • Firm sales order allocations: 940 units (held at the documented default)
  • Protected safety stock: 250 units (held at the documented default)
  • Quality hold or blocked stock: 80 units (held at the documented default)

Working through the calculation

  • The calculation starts from the formula this tool documents: Available to promise = available supply - firm allocations - protected safety stock - quality hold or blocked stock.
  • Available-to-promise quantity works out to 0 units at these inputs, and this is the headline figure for the scenario.
  • Committed, protected, and blocked inventory works out to 1,270 units at these inputs.
  • Available supply before new order works out to 900 units at these inputs.
  • Committed/protected share of available supply works out to 0 % at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where available supply before new order sits at 1,800 units and the headline result is 530 units, this scenario comes in 100% below the baseline at 0 units.
  • It computes the net quantity you can still promise after subtracting firm order allocations, protected safety stock, and any quality-held or blocked inventory from available supply. When the numbers land here, the stressed input is the lever to work; the walkthrough above shows exactly how much each output recovers as it climbs back toward the baseline.

Results at a glance

  • Available-to-promise quantity: 0 units (headline result)
  • Committed, protected, and blocked inventory: 1,270 units
  • Available supply before new order: 900 units
  • Committed/protected share of available supply: 0 %

Run it with your numbers

  • To rerun this with your own numbers, open the live Available to Promise calculator, set available supply before new order to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.