Cutting scrap: attack the unknown-cause share
1 · Split the scrap by cause status
List last quarter's scrap by cause. Two piles: known causes (someone can name the fix; it's unfixed for discipline or capex reasons) and unknown causes (the recurring residual that survives every workshop). Software doesn't fix the first pile. The second pile is the ML target, and in most plants it's 30-60% of the total.
2 · Why the unknown pile stays unknown
Because the causes are interactions. A material lot that runs fine (except with the tooling that's two weeks from change) except when zone 3 drifts 2 °C. No engineer charts that combination, and single-variable SPC never alarms. Unsupervised models watching hundreds of variables at once attribute exactly this shape of cause; it's why the largest published reductions (−58%, vendor-reported) come from this method.
3 · Run the economics first
The scrap calculator prices your annual scrap and the 30%/58% scenarios. Use fully loaded cost per scrapped unit (material, labor, energy, disposal) not material alone; the difference is usually 2-3×.
4 · Pilot on your worst line, on your own data
Demand a pilot on your line's historian data with a dated first-insight commitment, and judge it on confirmed root causes per month. Fast unsupervised platforms make this a days-not-quarters exercise; the pilot design matters more than the vendor logo.
Leave with the number, not a bookmark.
All four loss calculators (downtime, OEE, scrap, energy) in one Excel sheet, with conservative / typical / best-published scenario columns. Built for your budget meeting.