The study of the extent to which systematic and random factors are affecting our ability to correctly measure some phenomenon Observed Result = true unknown value error .
Why is MSA important?
- Incorrect decisions.
- Greater sample sizes required
- Understates capability indices.
- A bad one might be measured as good.
- A good one might be measured as bad.
When is MSA implemented?
- Before any data collection
- Prior to a process capability study.
- Key characteristic or process is not capable.
- Measurement system is suspected of being a significant source of variation.
- There are major changes to the measurement system.
- Before conducting an improvement study.
- Criterion to accept new measuring equipment.
Elements of Measuring System
- Work piece (Part).
- Environment .