Guides
Short, practical explanations for the questions that come up in daily quality work, each with a worked example and a link to the matching tool.
Cpk vs Ppk: what is the difference?
Cpk and Ppk use the same formula with a different sigma. Learn when each one applies, why they differ and what a gap between them tells you, with a worked example.
What is a good Cpk value?
Cpk 1.0, 1.33, 1.67 or 2.0? What the numbers mean in defects per million, typical customer requirements and how confident you can be with your sample size.
Measurement system analysis (MSA) step by step
The order of studies that proves a gauge can be trusted: resolution, type 1 study, linearity and bias, Gage R&R and attribute agreement, with acceptance criteria.
PPAP capability requirements explained
What the AIAG PPAP manual asks for in the initial process study: Ppk 1.67 or Cpk 1.33, stability, special characteristics and what to do when a characteristic falls short.
Nelson rules explained with examples
The eight Nelson rules for control charts: what pattern each one detects, what usually causes it and which rules to switch on for your process.