Process Behavior Charts
Upper and lower limits help to determine whether a process is in control or not. Many measurements will be needed to find a statistical norm.
p Charts help evaluate the proportion of defects, or nonconforming process. Always ensure that your data is properly defined and acquired or the p Charts will give an interpretation that is not reliable against the problem presented.
p Charts will have a center line, and upper and lower limit. If the process is in control limits then these data sets should reside within the upper and lower limits of 3 standard deviations. The greater the sample size the greater the statistical accuracy.
np Charts determine the number of defects, while u and c Charts evaluate the number of occurrences per unit produced.
What does these stages mean: Fine the Process, Set Limits for Remainder of the Initial Run, Set Limits for a Future Run
Long runs are not always needed, short runs can give good data if it is very precise, and additional precautions should be taken.
What is the difference between SPC and APC?
What is the difference between Binomial Distribution, Poisson Distribution, Hypergeometric Distribution, Nominal Distribution, Exponential Distribution,
