S&OP, Demand Planning & Forecasting worked example

Customer Forecast Reliability at 65% forecast attainment: a worked example

This worked example runs the customer forecast reliability numbers for a tougher week than the baseline: 65% forecast attainment instead of the typical 90%. Estimate customer forecast reliability for sandop, demand planning and forecasting using production-ready inputs so teams can confirm whether capacity can cover demand before committing the schedule.

The inputs for this scenario

  • Forecast Units per Planning Cycle: 4 units / cycle (held at the documented default)
  • Number of Planning Cycles Available: 480 cycles (held at the documented default)
  • Forecast Attainment (uptime equivalent): 65 % (the input this scenario stresses; the baseline uses 90)
  • Usable-Forecast Rate (first-pass yield): 97 % (held at the documented default)

Working through the calculation

  • The calculation starts from the formula this tool documents: Gross customer forecast reliability capacity = customer forecast reliability output per cycle × available customer forecast reliability cycles.
  • Good customer forecast reliability capacity works out to 1,211 units at these inputs, and this is the headline figure for the scenario.
  • Gross customer forecast reliability capacity works out to 1,920 units at these inputs.
  • Customer forecast reliability downtime loss works out to 672 units at these inputs.
  • Customer forecast reliability yield loss works out to 37.44 units at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where forecast attainment sits at 90% and the headline result is 1,676 units, this scenario comes in 27.78% below the baseline at 1,211 units.
  • Use it when converting a customer's stated forecast into your master production schedule or material plan, especially for customers with a track record of over-forecasting. 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

  • Good customer forecast reliability capacity: 1,211 units (headline result)
  • Gross customer forecast reliability capacity: 1,920 units
  • Customer forecast reliability downtime loss: 672 units
  • Customer forecast reliability yield loss: 37.44 units

Run it with your numbers

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

Last reviewed 2026-05-12.