Defining and Explaining Quality Control

A customer-based definition of quality

What does the word quality mean to you? For most people, quality is associated with the idea of a product or service that’s well done, looks good, and does its job well. We think of a quality product as one that lasts, holds up well under use, and doesn’t require constant repair. A quality product or service should meet a high standard in many areas, such as form, features, reliability, and usability.

Most people use the word quality to mean “having a high degree of excellence,” but like beauty, quality is in the eye of the beholder. If a consumer’s desire is to have basic transportation at a low price, he would buy a Toyota rather than a Lexus. The Toyota may be a lesser grade of car, but is it of lower quality than the Lexus? That’s up to the consumer to decide. The definition of quality changes over time. The Ford Model T was once thought of as a quality product, but if a dealership sold it today, it would be in the same quality class as the Yugo. Consumers’ quality standards for cars have changed over time, just like they have for other products.

As products and services evolve, consumer expectations tend to increase so that yesterday’s quality product becomes tomorrow’s junk. What do these facts mean to your business? Quality, in the eyes of a business, revolves around meeting customer expectations — expectations that may be stated or implied. Repeat business is probably the most basic measure of quality, because customers vote on the quality of your product or service with their pocketbooks. But unlike political elections, your customers vote daily, and new opposing candidates appear just as often to try to win your customers’ votes.

The statistical definition of quality

As you may expect, the statistical definition of quality is a little more precise than other definitions. When you measure quality statistically, you look for variation in a measurement between what the customer asks for and what you produce. The less variation you have, the higher the quality of your product or service.

All processes have some natural variation; you use statistics to detect abnormal variation that could cause you to produce a bad product or service. You can also use statistics to avoid testing every item that you produce. By testing a sample of what you make or deliver, you can use statistics to measure its quality and find out whether it meets customer requirements.

Setting Quality Standards

After you as an organization decide on a definition of quality, you need standards against which to measure your quality. Why? Many standards are driven by the desire to safeguard the health and well-being of the people who use the products or services companies provide. Quality standards also are critical in support of international trade. Almost every industry has an association or trade group that sets quality standards against which companies can measure the quality of their products or services. Industries also have their own government- or businesssupported standards bodies for products important to them. The International Organization for Standardization (ISO) is an international body made up of the national standards organizations for almost every country.

Preventing Errors with Quality Assurance

Quality assurance focuses on the ability of a process to produce or deliver a quality product or service. This method differs from quality control in that it looks at the entire process, not just the final product. Quality control is designed to detect problems with a product or service; quality assurance attempts to head off problems at the pass by tweaking a production process until it can produce a quality product.

Defining and Explaining Quality Control

Don’t get us wrong; we’re not saying that quality assurance and quality control are unrelated. By continually improving your process, you improve the quality of your product or service. Probably the most well-known technique for improving a process is called the Plan-Do-Check-Act, or the PDCA Cycle. This simple but powerful tool requires you to

_ Plan improvements to your process by looking for problems that affect the quality of your product or service.

_ Make improvements by implementing small changes to minimize disruption to your process.

_ Check production results to see if you’ve actually made an improvement.

_ Act on what you discover and roll it out to the entire process.