In his 1979 book Quality Is Free, Philip Crosby defined quality as “conformance to requirements.”
In a 1995 interview with IndustryWeek he explained the idea. “Conventionally, quality is always looked at as goodness, as gold-plating,” he said. But “you can’t manage with goodness as your definition of quality.” Instead: “It means doing exactly what you said you were going to do — that’s really the definition of quality.”