this: Quality (disambiguation)
In the vernacular, quality can mean a high degree of excellence (“a quality product”), a degree of excellence or the lack of it (“work of average quality”), or a property of something (“the addictive quality of alcohol”). Distinct from the vernacular, the subject of this article is the business interpretation of quality.

Variations of a business definition

Business has tried to define quality in a producer-consumer context, with the following variations:

1. ISO 9000: "Degree to which a set of inherent characteristic fulfills requirements." The standard defines requirement as need or expectation.
2. Six Sigma: "Number of defects per million opportunities." The metric is tied in with a methodology and a management system.
3. Philip B. Crosby: "Conformance to requirements." The difficulty with this is that the requirements may not fully represent customer expectations; Crosby treats this as a separate problem.
4. Joseph M. Juran: "Fitness for use." Fitness is defined by the customer.
5. Noriaki Kano and others, presenting a two-dimensional model of quality: "must-be quality" and "attractive quality." The former is near to the "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."
6. Robert Pirsig: "The result of care."
7. 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.

   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."

   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.

   Improvement of quality

   Many techniques and concepts, often overlapping, have evolved to improve product or service quality, including:

   • statistical process control (SPC)
   • Zero Defects
   • Six Sigma
   • Malcolm Baldrige National Quality Award
   • quality circles
   • requirements analysis

   • total quality management (TQM)
   • theory of constraints (TOC)
   • quality management systems
   • business process management (BPM)
   • capability maturity models
   • verification and validation