What Is Quality?
Quality is the totality of features and characteristics of a product or service that bear on its ability to satisfy stated or implied needs.
The term “quality” is not used to express a degree of excellence in a comparative sense nor is it used in a quantitative sense for technical evaluations.
When it is necessary to identify the quality in these terms, then the specific and appropriate adjective should be used. For example:
- Relative Quality. Should be used where products or services are ranked on a relative basis in the degree of excellence or some comparative sense.
- Quality Level, Quality Measure. Should be used where precise technical evaluations are carried out in a quantitative sense.
In a contractual environment, needs are identified and/or specified, whereas in other environments, implied needs should be identified and defined where appropriate.
Where possible, the needs (specifications/requirements), wants, and expectations of the customer ought to be identified and defined.
Quite often we must recognize that our needs can change over time. This implies periodic revision of requirements. Generally, the flow of change is as follows:
- Needs become obsolete.
- Wants become needs.
- Expectations become wants.
- Other expectations become our expectations.
- The cycle repeats.
Needs are usually translated into features and characteristics with specified criteria based on “the” specific customer. These needs may include—but are not limited to—aspects of usability, safety, availability, economics, environment, reliability, and maintainability.
Product and/or service quality is always influenced by many stages of interactive activities (negotiation) and optimization of related activities, such as: design, production, service operation, maintenance, financial, and so forth.
We must always be aware that the economic achievement of satisfactory quality involves ALL stages of the quality loop as a whole. It does not matter that sometimes we do identify some stages but not others.
When we do identify the stages, we do so only for emphasis. For example: quality attributable to design or quality attributable to service or quality attributable to implementation or quality attributable to production, and so forth.
Remember that quality overall is defined by the customer. Unless the needs, wants, and expectations of the customer are satisfied and/or are exceeded, there is no quality.
However, some other definitions may also be appropriate, such as fitness for use (the Juran traditional definition); the price of conformance/nonconformance (the Crosby definition); continual improvement (the Deming definition), and so forth.
All these definitions represent “some” facet of quality, and in all cases a fuller explanation is required. While differences must be recognized, the emphasis of quality is—or ought to be—on the functional use/cost relationship.