Advanced Planning, Scheduling & APS worked example

Production Schedule Stability at 75% inside protected window: a worked example

What does the result look like when inside protected window reaches 75%? The full calculation is worked below with real intermediate numbers. a production planner needs to quantify how much schedule churn is disrupting execution

The inputs for this scenario

  • Changed production orders: 26 orders (unchanged)
  • Disruption cost per change: 145 $ / change (unchanged)
  • Inside protected window: 75 % (raised for this scenario; the documented default is 65)
  • Replanning and communication cost: 500 $ (unchanged)

Working through the calculation

  • Applying the documented formula (Protected-window churn cost = changed orders × disruption cost per change × inside protected window) to the inputs above produces each figure below.
  • At this operating point the engine returns 3,328 $ churn impact for schedule churn impact, the number this scenario is built around.
  • At this operating point the engine returns 128 $ / change for disruption cost per change.
  • At this operating point the engine returns 2,828 $ churn impact for protected-window churn cost.
  • At this operating point the engine returns 500 $ for replanning and communication cost.

How this compares with the baseline

  • Against the tool's baseline example, where inside protected window sits at 65% and the headline result is 2,951 $ churn impact, this scenario comes in 12.78% above the baseline at 3,328 $ churn impact.
  • A figure at this level is achievable when inside protected window is genuinely sustained, not just peaked for a shift. It treats all in-window changes as equally disruptive, but a change one hour before run is far costlier than one a day out; for fine analysis, weight by proximity to execution.

Results at a glance

  • Schedule churn impact: 3,328 $ churn impact (headline result)
  • Disruption cost per change: 128 $ / change
  • Protected-window churn cost: 2,828 $ churn impact
  • Replanning and communication cost: 500 $

Run it with your numbers

  • Every input above is editable in the live Production Schedule Stability calculator, which recalculates instantly and can be shared with the inputs intact.

Last reviewed 2026-05-12.