Scrap Rate
Scrap rate is the percentage of produced material or units that cannot be accepted or economically reworked.
What this term means in maintenance
Scrap rate is the percentage of produced material or units that cannot be accepted or economically reworked.
Formula
Scrap rate = Scrap quantity ÷ Total production quantity × 100
Practical example
A line produces 2,000 parts and 60 are scrapped.
Scrap rate = 3%
Equipment-related causes
Scrap may result from:
- Incorrect settings
- Tool wear
- Poor calibration
- Temperature variation
- Vibration
- Sensor failure
- Misalignment
- Process instability
Use
Scrap trends help identify quality loss, equipment deterioration, and improvement opportunities.
Common mistake
Excluding startup scrap or recording it separately without reconciliation can understate total loss.
Related concepts
Related maintenance terms
Keep exploring connected CMMS, reliability, and maintenance planning terms.
Production Yield
Production yield is the proportion of input or total produced quantity that becomes acceptable output without being lost as scrap or rejected material.
Production Rework Rate
Production rework rate is the percentage of output requiring additional processing or correction before it can meet acceptance requirements.
Quality Rate
Quality rate is the OEE component measuring the proportion of total production that meets the defined good-output requirement.
Scrap Rate FAQs
- What is scrap rate?
Scrap quantity divided by total production quantity, multiplied by 100.
- What equipment problems can cause scrap?
Tool wear, calibration error, temperature, vibration, settings, sensors, and alignment.
- Is rework included in scrap?
Normally no. Scrap is unrecoverable; rework requires additional processing.