Process Capability Calculator (Cp, Cpk, Pp, Ppk)
Process Capability Calculator (Cp, Cpk, Pp, Ppk): a planned Super Calculator tool. Stub page: the tool, its formula and a worked example are not published yet.
Process Capability Calculator (Cp, Cpk, Pp, Ppk) is a planned calculator in the engineering section of Super Calculator, covering quality and reliability engineering.
What this calculator will compute
Inputs: upper and lower specification limits, process mean, standard deviation or subgroup data, subgroup size and sigma estimation method.
Outputs: Cp, Cpk, Pp, Ppk, estimated defects per million, sigma level and process centering index.
Formula, recorded as scope and not yet verified against a primary source: Cp = (USL - LSL) / (6 sigma_within); Cpk = min((USL - mu)/(3 sigma_within), (mu - LSL)/(3 sigma_within)). Pp and Ppk use the overall standard deviation instead of the within-subgroup estimate. Within-subgroup sigma is estimated as Rbar/d2 per the AIAG SPC reference manual.
Status
This page is a stub. The calculator is not built, no figure on this page has been verified against the authority that sets it, and nothing here should be used to make a decision. The page exists so that the site structure is complete and so that articles can link this concept on first mention.
The stub carries noindex, nofollow and is excluded from the sitemap.