Process Analysis for Normal Condition

Watching Y and X

Y is the result of the process. Y is the quality of productions. Watching Y tells us the trend of quality. And if it changes, we control the quality.

Watching Y is often the second move. We may notice after a lot of rejects are made.

Watching X is the first move. X is the cause of the process. X is, for example, temperture of the facilities, materials and tools.

If we do not know the X of the quality trouble, we estimate the X . The PDCA of estimation of X will raise the level of watching.