ERP & MRP Planning worked example

Forecast Accuracy at 65% target forecast accuracy: a worked example in erp & mrp planning

Suppose target forecast accuracy falls to 65%. This page works the full calculation at that level so you can see exactly which result moves and by how much. Calculate forecast accuracy from demand that landed within tolerance versus total actual demand.

The inputs for this scenario

  • Demand within forecast tolerance: 9,200 units (held at the documented default)
  • Total actual demand: 10,000 units (held at the documented default)
  • Target forecast accuracy: 65 % (the input this scenario stresses; the baseline uses 90)

Working through the calculation

  • The calculation starts from the formula this tool documents: Forecast accuracy = demand within forecast tolerance ÷ total actual demand × 100.
  • Forecast accuracy works out to 92 % at these inputs, and this is the headline figure for the scenario.
  • Forecast accuracy gap to target works out to -27 points at these inputs.
  • Demand within forecast tolerance works out to 9,200 units at these inputs.
  • Total actual demand works out to 10,000 units at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where target forecast accuracy sits at 90% and the headline result is 92 %, this scenario lands almost exactly on the baseline at 92 %.
  • It computes the share of total actual demand that landed within forecast tolerance and compares it against your accuracy target. 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

  • Forecast accuracy: 92 % (headline result)
  • Forecast accuracy gap to target: -27 points
  • Demand within forecast tolerance: 9,200 units
  • Total actual demand: 10,000 units

Run it with your numbers

  • To rerun this with your own numbers, open the live Forecast Accuracy calculator, set target forecast accuracy to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.