Rotational Molding worked example

Mold Arm Utilization at 99% target arm utilization: a worked example

What does the result look like when target arm utilization reaches 99%? The full calculation is worked below with real intermediate numbers. Use it when mold arm utilization in rotational molding needs a clean rate and gap-to-target you can put on a tier board.

The inputs for this scenario

  • Arms actively molding parts: 8 units (unchanged)
  • Total mold arms on the machine: 250 units (unchanged)
  • Target arm utilization: 99 % (raised for this scenario; the documented default is 95)

Working through the calculation

  • Applying the documented formula (Mold Arm Utilization rate = affected amount ÷ total amount) to the inputs above produces each figure below.
  • At this operating point the engine returns 3.2 % for rate, the number this scenario is built around.
  • At this operating point the engine returns 95.8 points for gap to target.
  • At this operating point the engine returns 8 count for affected count.
  • At this operating point the engine returns 250 count for total count.

How this compares with the baseline

  • Against the tool's baseline example, where target arm utilization sits at 95% and the headline result is 3.2 %, this scenario lands almost exactly on the baseline at 3.2 %.
  • A figure at this level is achievable when target arm utilization is genuinely sustained, not just peaked for a shift. It counts arm occupancy, not cycle quality — an arm loaded with a slow-curing or oversized mold can hurt throughput even at 100% utilization.

Results at a glance

  • Rate: 3.2 % (headline result)
  • Gap to target: 95.8 points
  • Affected count: 8 count
  • Total count: 250 count

Run it with your numbers

  • Every input above is editable in the live Mold Arm Utilization calculator, which recalculates instantly and can be shared with the inputs intact.

Last reviewed 2026-05-12.