| Quality control emphasizes testing of products to uncover defects, and reporting to management who make the decision to allow or deny the release, whereas quality assurance attempts to improve and stabilize production, and associated processes, to avoid, or at least minimize, issues that led to the defects in the first place.[citation needed] For contract work, particularly work awarded by government agencies, quality control issues are among the top reasons for not renewing a contract. |
| Total quality control" is a measure used in cases where sales decrease despite implementation of statistical quality control techniques or quality improvements. If the original specification does not reflect the correct quality requirements, quality cannot be inspected or manufactured into the product. For instance, the parameters for a pressure vessel should include not only the material and dimensions, but also operating, environmental, safety, reliability and maintainability requirements. |
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