Quality in business, engineering and manufacturing has a pragmatic interpretation as the non-inferiority or superiority of something. Quality is a perceptual, conditional and somewhat subjective attribute and may be understood differently by different people. Consumers may focus on the specification quality of a product/service, or how it compares to competitors in the marketplace. Producers might measure the conformance quality, or degree to which the product/service was produced correctly.
Numerous definitions and methodologies have been created to assist in managing the quality-affecting aspects of business operations. Many different techniques and concepts have evolved to improve product or service quality. There are two common quality-related functions within a business. One is quality assurance which is the prevention of defects, such as by the deployment of a quality management system and preventative activities like failure mode and effects analysis (FMEA). The other is quality control which is thedetection of defects, most commonly associated with testing which takes place within a quality management system typically referred to as verification and validation.
The common element of the business definitions is that the quality of a product or service refers to the perception of the degree to which the product or service meets the customer's expectations. Quality has no specific meaning unless related to a specific function and/or object. Quality is a perceptual, conditional and somewhat subjective attribute.
The business meanings of quality have developed over time. Various interpretations are given below:
- ISO 9000: "Degree to which a set of inherent characteristics fulfills requirements." The standard defines requirement as need or expectation.
- Six Sigma: "Number of defects per million opportunities."
- Subir Chowdhury: "Quality combines people power and process power."
- Philip B. Crosby: "Conformance to requirements." The requirements may not fully represent customer expectations; Crosby treats this as a separate problem.
- Joseph M. Juran: "Fitness for use." Fitness is defined by the customer.
- Noriaki Kano and others, present a two-dimensional model of quality: "must-be quality" and "attractive quality." The former is near to "fitness for use" and the latter is what the customer would love, but has not yet thought about. Supporters characterize this model more succinctly as: "Products and services that meet or exceed customers' expectations."
- Robert Pirsig: "The result of care."
- Genichi Taguchi, with two definitions:
- a. "Uniformity around a target value." The idea is to lower the standard deviation in outcomes, and to keep the range of outcomes to a certain number of standard deviations, with rare exceptions.
- b. "The loss a product imposes on society after it is shipped." This definition of quality is based on a more comprehensive view of the production system.
- American Society for Quality: "A subjective term for which each person has his or her own definition. In technical usage, quality can have two meanings:
- a. The characteristics of a product or service that bear on its ability to satisfy stated or implied needs;
- b. A product or service free of deficiencies."
- Peter Drucker: "Quality in a product or service is not what the supplier puts in. It is what the customer gets out and is willing to pay for."
- W. Edwards Deming: concentrating on "the efficient production of the quality that the market expects," and he linked quality and management: "Costs go down and productivity goes up as improvement of quality is accomplished by better management of design, engineering, testing and by improvement of processes."
- Gerald M. Weinberg: "Value to some person".