Understanding Unit Rework Rate
How we calculate. Rework % = units sent to rework ÷ total units × 100. See our methodology and accuracy policy .
Real-world scenario: A typical Unit Rework Rate case uses rework units 40 and total units 1000. Enter the same figures below to reproduce the worked path.
What is Unit Rework Rate?
A quality-cost KPI distinct from scrap (scrapped forever) and FPY (first-pass success). Rework consumes capacity even when units eventually pass.
- Rework = returned for correction
- Same UOM as total
- Pairs with FPY and scrap
The Formula
Worked Example
Common Use Cases
- Cost of poor quality: rework load
- Cell design: rework loops
- Supplier quality: incoming rework
Pro Tips
- Don’t double-count multi-loop rework unless intentional
- Separate cosmetic vs functional
- Watch hidden offline rework
| Scenario | When to use |
|---|---|
| Percent of a number | Finding a part of a whole (tax, tip, score) |
| Percent change | Comparing old vs new values |
Limitations: Unit Rework Rate results are educational manufacturing and lean/TPM planning aids—not process-safety, quality-system, or financial advice. Confirm definitions with your MES/SCADA and quality policies.
Common mistakes
- Swapping part and whole: The denominator must be the full total, not a subset.
- Rounding too early: Carry extra decimal places through multi-step work before rounding the final percent.
- Mixing percent and decimal forms: Enter rates in the format the calculator labels expect.
The worked example for unit rework rate was verified with the calculator form on this page—enter the same values to confirm the result.
When to use this calculator
- Use this page when your wording matches unit rework rate and the form labels on screen.
- Use percent of a number for “what is X% of Y?” problems.
- Use number is what percent when you know part and whole and need the percent.
Still unsure about unit rework rate? Start with the quick answer above, then open the linked calculator that matches your wording.
❓ Frequently Asked Questions
How do I use this unit rework rate calculator?
For unit rework rate, enter the values labeled on the form, then press Calculate. Compare the result to the worked example on this page.
What formula does this page use?
See the quick answer and formula box above for unit rework rate—the same percentage calculator expression is applied to your inputs.
What if my result looks wrong?
When checking unit rework rate, re-check part vs whole (or rate vs base), rounding, and whether percents were entered as 25 rather than 0.25 when the form expects percents.
Authoritative References
For OEE and manufacturing KPI definitions, consult: