Total Quality Control is the most important inspection control of all in cases where, despite statistical quality control techniques or quality improvements implemented, sales decrease.
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 ( see on the Wikipedia).
Quality control in project management
In project management, quality control requires the project manager and the project team to inspect the accomplished work to ensure that it’s aligned with the project scope.