S&OP, Demand Planning & Forecasting worked example

Bias Correction Savings at 43% share of bias eliminated by retuning: a worked example

Suppose share of bias eliminated by retuning falls to 43%. This page works the full calculation at that level so you can see exactly which result moves and by how much. Estimates the cost savings from removing systematic over- or under-forecast bias across a demand stream.

The inputs for this scenario

  • Annual units under biased forecast: 9,000 units (held at the documented default)
  • Cost of forecast bias per unit: 6.5 $/unit (held at the documented default)
  • Share of bias eliminated by retuning: 43 % (the input this scenario stresses; the baseline uses 60)
  • One-time model retuning cost: 1,800 $ (held at the documented default)

Working through the calculation

  • The calculation starts from the formula this tool documents: Total savings = biased units x cost of bias per unit x bias removed % + retuning cost.
  • Total bias correction savings cost works out to 26,955 $ at these inputs, and this is the headline figure for the scenario.
  • Bias correction savings cost per unit works out to 3 $ / piece at these inputs.
  • Variable bias correction savings cost works out to 25,155 $ at these inputs.
  • Fixed bias correction savings adder works out to 1,800 $ at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where share of bias eliminated by retuning sits at 60% and the headline result is 36,900 $, this scenario comes in 26.95% below the baseline at 26,955 $.
  • It computes total savings from removing a share of forecast bias across your biased volume, plus the fixed retuning cost, and expresses it per unit. 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

  • Total bias correction savings cost: 26,955 $ (headline result)
  • Bias correction savings cost per unit: 3 $ / piece
  • Variable bias correction savings cost: 25,155 $
  • Fixed bias correction savings adder: 1,800 $

Run it with your numbers

  • To rerun this with your own numbers, open the live Bias Correction Savings calculator, set share of bias eliminated by retuning to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.