Histogram as a spc tool, is a useful tool to show the distribution of data collected over a time period. The shape of the distribution provides information on whether the variations in a process is stable (random or natural variation) or unstable (non random or externally influence variation)
– Simple graphical display or “Bird’s eyes view” of the variation in a set of data according to their frequency of occurrences.
– Quick estimate of the mean of a distribution
– Information on the behavior of a process on whether its variations are natural or abnormal, and whether it meets specification or not.