Basic Principles of Statistical Process Control
- No two things are exactly alike
- Variation in a product or process can be measured
- Things Vary according to a definite pattern
- Whenever things of the same kind are measured, a large group of the measurements will tend to cluster around the middle.
- It is possible to determine the shape of the distribution curve for the measured Output (Parts produced, transaction) by any process
- Variation is due to assignable causes tend to distort the Normal distribution Curve.