S&OP, Demand Planning & Forecasting worked example

Monthly Forecast Volatility at 99% planning system availability: a worked example

Push planning system availability up to 99% and the picture changes. This example computes every intermediate figure at that operating point. Use it when monthly forecast volatility in s and op, demand planning and forecasting is being asked to take on more work and you need to know if there is room.

The inputs for this scenario

  • Forecast revisions processed per planning run: 4 units / cycle (unchanged)
  • Planning runs available in the month: 480 cycles (unchanged)
  • Planning system availability: 99 % (raised for this scenario; the documented default is 90)
  • Revisions accepted without rework (first pass): 97 % (unchanged)

Working through the calculation

  • Applying the documented formula (Gross monthly forecast volatility capacity = monthly forecast volatility output per cycle × available monthly forecast volatility cycles) to the inputs above produces each figure below.
  • At this operating point the engine returns 1,844 units for good monthly forecast volatility capacity, the number this scenario is built around.
  • At this operating point the engine returns 1,920 units for gross monthly forecast volatility capacity.
  • At this operating point the engine returns 19.2 units for monthly forecast volatility downtime loss.
  • At this operating point the engine returns 57.02 units for monthly forecast volatility yield loss.

How this compares with the baseline

  • Against the tool's baseline example, where planning system availability sits at 90% and the headline result is 1,676 units, this scenario comes in 10% above the baseline at 1,844 units.
  • It computes the number of forecast revisions your process can fully absorb per month after subtracting system-downtime losses and first-pass rework. The value of this scenario is the size of the gap it exposes: that gap, priced out over a year, is the budget you can justify spending to close it.

Results at a glance

  • Good monthly forecast volatility capacity: 1,844 units (headline result)
  • Gross monthly forecast volatility capacity: 1,920 units
  • Monthly forecast volatility downtime loss: 19.2 units
  • Monthly forecast volatility yield loss: 57.02 units

Run it with your numbers

  • Every input above is editable in the live Monthly Forecast Volatility calculator, which recalculates instantly and can be shared with the inputs intact.

Last reviewed 2026-05-12.