Building Materials Manufacturing worked example

Cement Mill Throughput at 63% mill operating efficiency after stops and rate loss: a worked example

Here is what the math looks like when conditions slip. We hold every other input steady and drop mill operating efficiency after stops and rate loss to 63%, then walk the calculation through step by step. Calculate effective cement mill throughput in tons per hour after downtime and rate loss.

The inputs for this scenario

  • Good cement produced by the mill: 3,200 tons (held at the documented default)
  • Cement mill producing runtime: 24 hr (held at the documented default)
  • Mill operating efficiency after stops and rate loss: 63 % (the input this scenario stresses; the baseline uses 88)

Working through the calculation

  • The calculation starts from the formula this tool documents: Raw cement mill throughput = good cement produced by the mill รท cement mill producing runtime.
  • Cement Mill Throughput works out to 84 tons / hr at these inputs, and this is the headline figure for the scenario.
  • Raw cement mill throughput works out to 133 tons / hr at these inputs.
  • Mill operating efficiency after stops and rate loss works out to 63 % at these inputs.
  • Cement mill producing runtime works out to 24 hr at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where mill operating efficiency after stops and rate loss sits at 88% and the headline result is 117 tons / hr, this scenario comes in 28.41% below the baseline at 84 tons / hr.
  • The practical read: the gap between this scenario and the baseline is entirely attributable to mill operating efficiency after stops and rate loss, so recovering it is worth quantifying in dollars before considering equipment or staffing changes. It assumes a single blended product and a representative period; mixing cement types with very different Blaine targets in one window will blur the true throughput for any one grade.

Results at a glance

  • Cement Mill Throughput: 84 tons / hr (headline result)
  • Raw cement mill throughput: 133 tons / hr
  • Mill operating efficiency after stops and rate loss: 63 %
  • Cement mill producing runtime: 24 hr

Run it with your numbers

  • To rerun this with your own numbers, open the live Cement Mill Throughput calculator, set mill operating efficiency after stops and rate loss to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.