quality control

Quality control is the hands-on testing and inspection that checks whether what was actually made meets the rules it was supposed to meet. If quality assurance is the kitchen's whole system for cooking well, quality control is the chef tasting each dish before it leaves the pass.

In practice QC means a laboratory and inspection function that samples raw materials, in-process material, and finished product, then runs the tests in the specification — assay, dissolution, content uniformity, microbial limits, appearance — and compares each result to the acceptance limits. Material is not released for use or sale until QC confirms it passes. QC also includes sampling plans, retained samples, and stability testing over time.

QC is necessary but not sufficient on its own: testing detects problems but does not prevent them. Because you cannot test quality into a product, QC works alongside good manufacturing practice and quality assurance, which build quality in from design and process onward.