Glass Container & Bottle Manufacturing worked example

Mold Changeover Time at 14% changeover contingency allowance: a worked example

This worked example runs the mold changeover time numbers for a tougher week than the baseline: 14% changeover contingency allowance instead of the typical 20%. Estimate IS machine mold changeover time for a bottle, jar, or container job using mold equipment workload, crew change rate, and normal setup allowance.

The inputs for this scenario

  • Mold sets to change: 12 mold sets (held at the documented default)
  • Mold change crew rate: 4 mold sets / hr (held at the documented default)
  • Changeover contingency allowance: 14 % (the input this scenario stresses; the baseline uses 20)

Working through the calculation

  • The calculation starts from the formula this tool documents: Base mold changeover time = mold equipment change workload รท measured mold change rate.
  • Required mold changeover time works out to 3.42 hr at these inputs, and this is the headline figure for the scenario.
  • Base mold changeover time works out to 3 hr at these inputs.
  • Changeover allowance applied works out to 14 % at these inputs.
  • Measured mold change rate works out to 4 pieces / min at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where changeover contingency allowance sits at 20% and the headline result is 3.6 hr, this scenario comes in 5% below the baseline at 3.42 hr.
  • Use it when scheduling article or color changes and quoting job-change windows so the production plan reflects real machine-open time, not just mechanical swap time. A result at this level usually justifies acting on the stressed input before touching anything else, because every other figure in the table is downstream of it.

Results at a glance

  • Required mold changeover time: 3.42 hr (headline result)
  • Base mold changeover time: 3 hr
  • Changeover allowance applied: 14 %
  • Measured mold change rate: 4 pieces / min

Run it with your numbers

  • To rerun this with your own numbers, open the live Mold Changeover Time calculator, set changeover contingency allowance to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.