Ceramic, Tile & Sanitaryware Manufacturing worked example

Rework Firing Load Time at 14% rework sorting and kiln-change allowance: a worked example

This scenario runs the rework firing load time calculation on the strong side: 14% rework sorting and kiln-change allowance, with every other input held at its documented default. a kiln team is deciding whether a rework load can fit into the available firing schedule

The inputs for this scenario

  • Rework tiles or fixtures to refire: 1,400 pieces (unchanged)
  • Rework firing clearance rate: 18 pieces / min (unchanged)
  • Rework sorting and kiln-change allowance: 14 % (raised for this scenario; the documented default is 12)

Working through the calculation

  • Applying the documented formula (Base rework kiln time = rework pieces to refire รท rework firing clearance rate) to the inputs above produces each figure below.
  • At this operating point the engine returns 88.67 min for required rework firing load time, the number this scenario is built around.
  • At this operating point the engine returns 77.78 min for base rework kiln time.
  • At this operating point the engine returns 14 % for rework firing allowance applied.
  • At this operating point the engine returns 18 pieces / min for rework firing clearance rate.

How this compares with the baseline

  • Against the tool's baseline example, where rework sorting and kiln-change allowance sits at 12% and the headline result is 87.11 min, this scenario comes in 1.79% above the baseline at 88.67 min.
  • Use it when scheduling rework firings, sizing spare kiln windows, or deciding whether to batch rework or run it as it arrives. Treat this as a target state: the delta against the baseline quantifies what the improvement is worth before you commit to chasing it.

Results at a glance

  • Required rework firing load time: 88.67 min (headline result)
  • Base rework kiln time: 77.78 min
  • Rework firing allowance applied: 14 %
  • Rework firing clearance rate: 18 pieces / min

Run it with your numbers

  • Every input above is editable in the live Rework Firing Load Time calculator, which recalculates instantly and can be shared with the inputs intact.

Last reviewed 2026-05-12.