Lean Manufacturing & Operations worked example

Changeover Frequency Impact at 65% target machine utilization: a worked example

Here is what the math looks like when conditions slip. We hold every other input steady and drop target machine utilization to 65%, then walk the calculation through step by step. Calculate the percentage of available time consumed by changeovers based on number of changeovers, average changeover duration, and total available time.

The inputs for this scenario

  • Total changeover time per shift: 60 min (held at the documented default)
  • Total available production time: 450 min (held at the documented default)
  • Target machine utilization: 65 % (the input this scenario stresses; the baseline uses 90)

Working through the calculation

  • The calculation starts from the formula this tool documents: Changeover % = (Total Changeover Time / Available Time) x 100.
  • Changeover time as % of available time works out to 13.33 % at these inputs, and this is the headline figure for the scenario.
  • Gap to utilization target works out to 51.67 points at these inputs.
  • Total changeover time works out to 60 count at these inputs.
  • Available production time works out to 450 count at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where target machine utilization sits at 90% and the headline result is 13.33 %, this scenario lands almost exactly on the baseline at 13.33 %.
  • The practical read: the gap between this scenario and the baseline is entirely attributable to target machine utilization, so recovering it is worth quantifying in dollars before considering equipment or staffing changes. It treats all changeover minutes as lost, but some setup can run external to the machine; it also says nothing about whether the remaining time is run efficiently.

Results at a glance

  • Changeover time as % of available time: 13.33 % (headline result)
  • Gap to utilization target: 51.67 points
  • Total changeover time: 60 count
  • Available production time: 450 count

Run it with your numbers

  • To rerun this with your own numbers, open the live Changeover Frequency Impact calculator, set target machine utilization to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.