At present, the transition of the enterprise to the built-in quality system is becoming relevant. To implement it, I have developed a methodology for introducing built- in quality. It allows you to determine the key characteristics (control points) of the technological process, since its main purpose is to identify defect-forming zones of defect-carrying products and determine ways that exclude their occurrence in mass production. Identification of defect-forming zones is carried out based on the results of FMEA, technical diagnostics, non-destructive testing, physical and technical analysis, and organizational and technical measures. This technique, as an element of built-in quality, does not require additional costs. It is based on the production technology operating at the enterprise, statistical results, technical diagnostics, production control and product testing. Regardless of any data array, fixing the quality indicators of any assessment of measurements or tests is reduced to obtaining an unambiguous answer: yes or no, which is, the product characteristic meets the specified requirements or does not.