What is the difference between quality assurance (QA) and qualilty control (QC)?

​Many people have asked me about the difference between Quality Assurance and Quality Control. Here is the summary:

ISO 9000 Definitions

Quality Control:

A part of quality management focused on fulfilling quality requirements.

Quality Assurance:

A part of quality management focused on providing confidence that quality requirements will be fulfilled.

Other Definitions

Quality Control is defined as The operational techniques and activities used to fulfill requirements for quality.
Quality Assurance is defined as All the planned and systematic activities implemented within the quality system that can be demonstrated to provide confidence that a product or service will fulfill requirements for quality.

Quality Control, is the physical verification that the product conforms to these planned arrangements by inspection, measurement, etc.
Quality Assurance is fundamentally focused on planning and documenting those processes to assure quality including things such as quality plans and inspection and test plans

Quality Control is the process involved in the system to ensure job management, competence and performance during the manufacturing of the product or service to ensure it meets the quality plan as designed.
Quality Assurance is a system for evaluating performance, service, of the quality of a product against a system, standard or specified requirement for customers.

Quality Control

  • What: The activities or techniques used to achieve and maintain the product quality, process and service.
  • How: Finding & eliminating causes of quality problems through tools & equipment, so that customer’s requirements are continually met.

Quality Assurance

  • What: Prevention of quality problems through planned and systematic activities including documentation.
  • How: Establish a good quality management system and the assessment of its adequacy & conformance audit of the operating system & the review of the system itself.

Quality Control measures and determines the quality level of products or services. It is a process itself.

Quality Assurance is a complete system to assure the quality of products or services. It is not only a process, but a complete system including also control. It is a way of management.