MANUFACTURING & PRODUCTION
Work out how many parts to start in order to end up with the number of good parts you actually need, given an expected scrap rate.
–
Parts to Start
–
Expected Scrap Qty
Parts to start = desired good parts / (1 – scrap rate). Expected scrap quantity = parts to start – desired good parts.
How it works
If a process loses a known percentage of parts to scrap, starting exactly the number of good parts you need will leave you short. Inflating the start quantity by the scrap rate covers the expected loss so the finished good count lands where you planned.
FAQ
Should I round the result up? Yes, always round the parts-to-start number up to a whole part, since a fractional part cannot be started or finished.
Related Guides
CNC Calculators · OEE Calculator · Part Cost Calculator
Spotted an error or have a suggestion for this calculator? Let us know →