5.3.4 (HL)—Quality control and quality assurance

Quality control detects defects in outputs through inspection or testing; quality assurance designs processes and standards to prevent defects.

Control is reactive at the product stage, while assurance builds reliability into inputs, training and procedures. Both need meaningful specifications and feedback.

Ask whether the activity finds a defect after production or prevents the cause before it occurs.

A final inspection rejects a cracked bottle (control); supplier checks and machine calibration prevent cracks (assurance).

More inspection cannot substitute for a poorly designed process.