Enter your specification limits and the process mean and standard deviation — or paste a column of measurements — to compute Cp, Cpk, Pp, Ppk, the process sigma level, DPMO and % yield. Includes capability interpretation bands, a bell-curve visual and the 1.5σ-shift convention. Six Sigma / SPC. Exports to Word & CSV.
⚠️ These indices assume a stable, in-statistical-control and normally-distributed process. Verify control with a control chart and check normality before trusting Cp/Cpk; non-normal or out-of-control data make these numbers misleading. Cp/Cpk use short-term (within-subgroup) variation; Pp/Ppk use long-term (overall) variation — label which σ you entered. The "process sigma level" applies the conventional 1.5σ long-term shift used in Six Sigma (so a 6σ process ≈ 3.4 DPMO). This is an engineering aid, not a substitute for a validated measurement system (MSA) or a qualified quality engineer. References: ASQ / Six Sigma DMAIC, ISO 22514, AIAG SPC.