QualityAdvisorsponsored by PQ Systems
Quality Assurance SPC statistical process control software for an organization’s continuous improvement program.
Home
Library
Classroom
Forum
Resources
About
PQ Systems
 
home > sqc

Untitled Document

Capability Indices: Pr

The Pr performance ratio is used to summarize the actual spread of the system compared to the spread of the specification limits (upper and lower). The lower the Pr value, the smaller the output spread. Pr does not consider process centering.

When the Pr value is multiplied by 100, the result shows the percent of the specifications that are being used by the variation in the process. Pr is calculated using the actual sigma (sigma of the individuals) and is the reciprocal of Pp. In other words, Pr = 1/Pp.

See also:
>How do I compare Cpk/Ppk to Cp/Pp?
>Cpk
>Cp
>Cr
>Cpm
>Ppk
>Pp
>Capability indices