Standard deviation (process capability)

An estimate of the variation of your process output. Minitab uses several types of standard deviation to capture different patterns of variation in a process:

·    Within-subgroup standard deviation (swithin): represents the variation within your subgroups. For example, the variation in the output of one worker, one shift, or one batch.

·    Between-subgroup standard deviation (sbetween): represents the variation between subgroups. For example, the variation between the output of different shifts or operators.

·    Between/within standard deviation (sB/W): a single value that accounts for the variation between subgroups and within subgroups.

·    Overall standard deviation (soverall): represents the variation of the entire process output, ignoring subgroups. It is calculated by combining data from all subgroups and treating them as a single sample. This is the variation the customer experiences because the distinction between subgroups disappears when the customer receives the process output.