Quality Control emphasizes testing of products to uncover defects
and reporting to management who make the decision to allow or deny
product release, whereas quality assurance attempts to improve and
stabilize production (and associated processes) to avoid, or at
least minimize, issues which led to the defect(s) in the first
place. For contract work, particularly work awarded by government
agencies, quality control issues are among the top reasons for not
renewing a contract.