Rotational Molding worked example

Insert Loading Time at 7.2% fatigue and handling allowance: a worked example

Suppose fatigue and handling allowance falls to 7.2%. This page works the full calculation at that level so you can see exactly which result moves and by how much. Insert loading time is the labor time an operator spends placing metal threaded inserts, brass bosses, or reinforcement plates into the rotomold before the tool is closed and charged with powder.

The inputs for this scenario

  • Insert placements required this batch: 120 units (held at the documented default)
  • Inserts loaded per operator-hour: 12 units / hr (held at the documented default)
  • Fatigue and handling allowance: 7.2 % (the input this scenario stresses; the baseline uses 10)

Working through the calculation

  • The calculation starts from the formula this tool documents: Base insert loading time time = required work รท processing rate.
  • Adjusted run time works out to 10.72 hr at these inputs, and this is the headline figure for the scenario.
  • Base run time works out to 10 hr at these inputs.
  • Allowance applied works out to 7.2 % at these inputs.
  • Process rate works out to 12 pieces / min at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where fatigue and handling allowance sits at 10% and the headline result is 11 hr, this scenario comes in 2.55% below the baseline at 10.72 hr.
  • It computes the total operator hours to load all inserts for a batch by dividing required insert placements by the loading rate, then adding a fatigue and handling allowance. When the numbers land here, the stressed input is the lever to work; the walkthrough above shows exactly how much each output recovers as it climbs back toward the baseline.

Results at a glance

  • Adjusted run time: 10.72 hr (headline result)
  • Base run time: 10 hr
  • Allowance applied: 7.2 %
  • Process rate: 12 pieces / min

Run it with your numbers

  • To rerun this with your own numbers, open the live Insert Loading Time calculator, set fatigue and handling allowance to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.