Tube, Pipe & Profile Forming worked example

Tube Scrap Rate at 68% target first-pass yield reference: a worked example

Here is what the math looks like when conditions slip. We hold every other input steady and drop target first-pass yield reference to 68%, then walk the calculation through step by step. Tube Scrap Rate is the share of a tube-forming run that ends up rejected - split seams, over-oval bends, wrinkles, wall failures - expressed as a percentage of everything produced.

The inputs for this scenario

  • Tubes scrapped in the run: 8 units (held at the documented default)
  • Total tubes produced in the run: 250 units (held at the documented default)
  • Target first-pass yield reference: 68 % (the input this scenario stresses; the baseline uses 95)

Working through the calculation

  • The calculation starts from the formula this tool documents: Tube Scrap Rate rate = affected amount รท 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 first-pass yield reference 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 first-pass yield reference, so recovering it is worth quantifying in dollars before considering equipment or staffing changes. A single scrap rate hides the mix of defect causes - a 3% rate from one bad setup is very different from 3% spread across many modes - so pair it with a Pareto of defect reasons before acting.

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 Tube Scrap Rate calculator, set target first-pass yield reference to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.