Refractories, Furnace Linings & Foundry Consumables worked example

Batch Mix Yield at 68% target scrap-rate ceiling: a worked example

Here is what the math looks like when conditions slip. We hold every other input steady and drop target scrap-rate ceiling to 68%, then walk the calculation through step by step. Batch Mix Yield here measures the defect rate of a poured batch — reject castings as a fraction of everything poured — so a foundry can judge how clean each melt-and-mold cycle ran.

The inputs for this scenario

  • Reject or scrap castings from the batch: 8 units (held at the documented default)
  • Total castings poured in the batch: 250 units (held at the documented default)
  • Target scrap-rate ceiling: 68 % (the input this scenario stresses; the baseline uses 95)

Working through the calculation

  • The calculation starts from the formula this tool documents: Batch Mix Yield rate = affected amount ÷ total amount.
  • Rate works out to 3.2 % at these inputs, and this is the headline figure for the scenario.
  • Gap to target works out to 64.8 points at these inputs.
  • Affected count works out to 8 count at these inputs.
  • Total count works out to 250 count at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where target scrap-rate ceiling sits at 95% and the headline result is 3.2 %, this scenario lands almost exactly on the baseline at 3.2 %.
  • The practical read: the gap between this scenario and the baseline is entirely attributable to target scrap-rate ceiling, so recovering it is worth quantifying in dollars before considering equipment or staffing changes. A batch rate is a lagging count — it tells you a batch went bad but not why, so pair it with defect-type Pareto data before you chase a root cause.

Results at a glance

  • Rate: 3.2 % (headline result)
  • Gap to target: 64.8 points
  • Affected count: 8 count
  • Total count: 250 count

Run it with your numbers

  • To rerun this with your own numbers, open the live Batch Mix Yield calculator, set target scrap-rate ceiling to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.