Is It Quality Assurance or Quality Control?

Exactly what are the subtleties between quality control and quality assurance?

Published: Tuesday, February 8, 2011 - 06:00

If a manufacturer were to ask its clients how they evaluated goods or services, the three most common metrics would be goods at a fair price, on-time delivery, and quality. Ask which could be most valuable and in all likelihood the most significant response would be quality. When included in the product, quality isn’t a cost but a powerful tool leading to the economic success of the business.

Therefore while a supply chain partner needs to control all three—fair price, on-time delivery, and quality—as they are highly interdependent, quality can be the pendulum that swings a company from low client retention to high.

My personal thoughts and opinions are that corporations recognizing quality possess a much higher client retention rate, build competitive boundaries, and thus build their top line without compromising the bottom line. I will admit that I have been muddled about the question myself during my career and since I speak to these individuals on a regular basis, I thought it was high time to sift through the definitions.

As defined by ISO 9000:

• Quality control—the operational techniques and activities that are utilized to fulfill requirements for quality
• Quality assurance—all those planned and systematic activities implemented to provide adequate confidence that the entity will fulfill requirements for quality

So what does this mean exactly?  Well, we can dissect it into these macro segments:

The quality control manager will probably be interested in product yield, reacts to changing conditions, focuses on the product, provides a production line function, and finds faults. The aim of quality control is to offer the highest quality of product or service to the client, thereby meeting or even exceeding the client requirements.

A quality control method is designed for the following:

• To provide regular checks so as to guarantee the correctness, completeness, and integrity of quality data
• To differentiate mistakes and to address them
• To file and record all the quality control procedures

The quality assurance manager will probably be interested in process yield, is proactive at investigating preventative steps and technologies, provides a staff function, and prevents defects. The aim of quality assurance is to apply a planned and systematic production process, such that confidence concerning the suitability of the product is maintained throughout the production process.

A quality assurance program adopts these principles:

• The product or service needs to be suitable and fit for the intended purpose.
• The methods used should be such that they decrease the errors and the shortcomings the first time through the manufacturing process. This means, that one has to come up with the right product, the first time.

On this basis, the quality control operation is interested in testing, inspection, and production line checkpoints and the quality assurance operation is interested in process definitions, proper selection of tools and methods, and adequate operator training.

The checkpoints and process definitions link together along these manufacturing stages:

• Raw material input
• Control of the manufacturing process
• Continual inspection and validation throughout the production process
• Deterministic testing
• Data acquisition and records

Quality control and quality assurance are often confused. Quality assurance is process oriented, whereas quality control is concerned mainly with the product. Quality assurance works at avoiding defects, whereas quality control works at locating defects.

Quality control emphasizes testing of products to discover defects, and reporting any defects to management, who then make the decision to allow or deny the release of those products. Quality assurance attempts to improve and stabilize production and related processes, to prevent, or at least minimize, any conditions that triggered product defects. Typically, quality control involves problem identification, problem analysis, problem correction, and feedback. Conversely, quality assurance involves data collection, problem trend analysis, process identification, process analysis, and process improvement. Simply put, quality control evaluates whether or not the final result is acceptable, while quality assurance makes sure that the processes being integrated satisfy the predetermined objectives.

Ideally with both programs in position, with properly identified goals and coherent goals, all quality demands are then satisfied by rigidly conforming to exact instructions, by performing sufficient checks at critical stages, by implementing with care the proven procedures, and by conducting professional testing and inspections during and after production.

About The Author

Pierre Huot

Pierre Huot founded Invisual E Inc. in 2009 in response to a desire to implement his vision to the market for identified needs for manufacturing. Huot's adherence to a customer-driven development approach combined with his strategic abilities to envision industry demands and help clients build brands, expand markets and grow revenues will ensure that the company addresses the growing, complex needs of the manufacturing industry. Huot possesses an MBA from the Richard Ivey School of Business and a bachelor's degree in chemical engineering from the University of Ottawa. He is the author of several published case studies and white papers.