What is Quality Control?

Dr. Joseph A DeFeo Knowledge

Today, the term “quality control” often means quality control and compliance. The goal is to comply with critical-to-quality requirements and international standards or regulatory authorities such as ISO 9000. In Japan, the term “quality control” retains a broader meaning. Their “total quality control” is equivalent to the term “business excellence.” In 1997, the Japanese Union of Scientists and Engineers (JUSE) adopted the term Total Quality Management (TQM) to replace Total Quality Control (TQC) to more closely align themselves with the more common terminology used in the rest of the world.

Quality Control (Process Control & Regulatory)

Quality control is the third universal process in the Juran Trilogy. The term “control of quality” first emerged in the early part of the twentieth century. At that time, the concept was beginning to expand from the then-prevailing after-the-fact inspection, or “detection”,  to what we now call “prevention”.

Why is Quality Control Needed?

When designing a product we create features to satisfy the customer needs. Quality control is the method carried out every day to assure we are making and delivering the product or service to the right targets. We maintain control of product features, or key product characteristics, required to meet customer needs. This consists of a system of product and process controls, which can provide stability to the operating process. A key product characteristic one that controls anticipated variation could significantly affect a product’s safety, compliance to government regulations, performance, or fit.

Quality Control Tools & Techniques

Quality control takes place by use of a simple feedback loop, as follows:

  1.  A sensor is “plugged in” to evaluate the actual quality of the control subject—the product or process feature in question. The performance of a process may be determined directly by evaluation of the process feature, or indirectly by evaluation of the product feature—the product “tells” on the process.
  2. The sensor reports the performance to an umpire. The umpire may be a computer or a person.
  3. The umpire also receives information on the quality goal or standard.
  4. The umpire compares actual performance to standard. If the difference is too great, the umpire energizes an actuator.
  5. The actuator stimulates the process (whether human or technological) to change the performance so as to bring quality into line with the quality goal.
  6. The process responds by restoring conformance.

Quality control maintains whatever was planned or designed. The QC methods enable an organization to reduce risk, which could lead to a failure, an injury or even death.


At Juran, we help organizations implement quality control procedures that produce optimum business results. Get in touch today to find out about more about our organizational health checks, process control audits and Q101 training.

Author: Dr. Joseph A DeFeo

Dr. Joseph A. DeFeo, Chairman and CEO of Juran, is recognized as one of the world’s leading experts on transformational change and breakthrough quality management.

For 28 years, Dr. DeFeo has worked as a trusted adviser helping business leaders increase sales, reduce costs and improve its customer experience through the deployment of performance excellence programs. These include Business Process Quality Management, Lean, Six Sigma, Strategy Deployment and Change Management. His recent publication, Juran’s Quality Essentials for Leaders, provides a concise message delivered for leaders to teach them how to embrace quality, not fight it, to be a globally competitive enterprise. Dr. DeFeo has co-authored three other popular texts.

DeFeo’s belief that a relentless customer focus and integrity drives business results was recently noted by Steve Denning of Forbes.com. A frequent motivational guest speaker at international conferences, Dr. DeFeo has presented in over 30 countries.