It seems like every few years somebody, somewhere around the world asks, “What is quality?” or “What does quality mean?” I recently had the opportunity to make my own attempt at addressing this question when it was asked by the Deutsche Gesellschaft für Qualität (German Society for Quality). Following is an English translation of my answer.
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An operational definition of the characteristic “quality”
Indirectly, quality is necessary for the long-term survival of a company and the economic well-being of a land. Such a qualitative explanation, however, fails to identify what quality is. ISO 9000:2005 defines quality as the “degree to which a set of inherent characteristics fulfills requirements.” Philip Crosby defined quality as “conformance to requirements” and not “goodness.” This is in contrast to the definition used by Walter A. Shewhart, the father of SPC, who considered quality to be “goodness.” Joseph Juran defined quality as “fitness for use,” which may be more accurate than the other definitions because it partially includes them. Yet none of these definitions are complete.
A product that is within specification but is useless because the customer’s specification was wrong is perhaps “good quality,” at least to use as a justification for rejecting the customer’s complaint; but it would be misguided to proudly display it as an example of a good-quality product. Although it’s possible that an out of specification product is exactly what a customer needs, due to an improper specification, it would not be correct to refer to a nonconforming product as good quality.
Simply using the term “good quality” is unclear when the most important aspect, quality, is not clearly defined.
Then how can we define quality in such a way that it incorporates the useful aspects of the previous definitions, yet is qualitative enough to be practical?
Donald J. Wheeler tells us that W. Edwards Deming once defined operational definitions as “...(1) a criterion to be applied to an object or a group of objects; (2) a test of compliance for the object or group; and (3) a decision rule for interpreting the test results as to whether the object or group is, or is not, in compliance.” He also explained it as “a procedure agreed upon for translation of a concept into measurement of some kind.”
To form an operational definition of quality, we need a criterion, a test, and an agreed-upon interpretation of the test. The criterion is quality, the tests are specifications, standards, and other evaluations achieved by means of quality function deployment (QFD) and voice of the customer (VOC) activities, and we should agree that all test requirements must be fulfilled to achieve the aspect, quality.
With such an operational definition, we can define quality as “the condition when a product or service conforms to requirements such as specifications, relevant standards, and the customer’s needs as they are determined to be when planning the product or service.”
Every few years, in different countries, this question arises. I think more important than the many answers that result is ensuring that there are plenty of quality professionals who seek to answer the question as well as ensure and improve the quality of their products and services.
My original German version of this article can be read here.
Comments
What is Quality?
Matthew,
I teach a section called "What is Quality?" as part of Ed Zunich's Practical Process Improvement program. His definition contains 5 dimensions...
1. Fit, form and function (does it do what it is supposed to?)
2. Price (what the customer is willing to pay)
3. Delivery (the customer wants it when they want it)
4. Image (brand, past experience and future promise)
5. Continuous Improvement (what is good enough today will not be tomorrow)
I like Ed's approach in viewing quality from the customers' perspective and the 5 dimensions always produces a lively debate within the training.
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