There are a lot of definitions for quality. Part of the problem in defining 'Quality' is that when one starts looking at it from different positions the problem of personal expectations comes into play. For example, what one person sees as 'quality' in a specific product often significantly differs from what someone else 'sees'. The American Society for Quality (ASQ) defines "quality" as "a subjective term for which each person has his or her own definition.
In technical usage, quality has two main meanings:
- The characteristics of a product or service that bear on its ability to satisfy stated or implied needs.
- A product or service free of deficiencies.
Quality can refer to:
- A specific characteristic of an object (the qualities of ice - i.e. its properties)
- The essence of an object (the quality of ice - i.e. "iceness")
- The achievement or excellence of an object (good quality ice - i.e. not of inferior grade)
- The meaning of excellence itself
This can also be related to a business.
The first meaning is technical, the second philosophical, the third practical, and the fourth metaphysical. The last two meanings are those most commonly used. Therefore, whereas the first two meanings admit that Quality can be positive, negative or neutral, the overwhelming association is that Quality is something to be desired.
Philosophy and common sense tend to see quality as related either to subjective feelings or to objective facts. The subject-object in question might be a concrete and functional (e.g. Arisotelian) value to be learnt and applied (a and b), or a psychic (e.g. platonic) ideal to be apprehended and represented (c). A third view tends to see quality not as a secondary value that something has, rather a primary truth which comprises apparent subjects and objects (d).
So the quality of something depends on the criteria being applied to it. Something might be good because it is useful, because it is beautiful, or simply because it exists. Determining or finding quality therefore involves an understanding of use, beauty and existence - what is useful, what is beautiful and what exists.
Many different techniques and concepts have evolved to improve product or service quality, including SPC, Zero Defects, Six Sigma, Malcolm Baldrige National Quality Award, quality circles, TQM, Theory of Constraints (TOC),Quality Management Systems (ISO 9000 and others) and continuous improvement.
The meaning for the term quality has developed over time. Various interpretations are given below:
- ISO 9000 3.1.1 "quality - Degree to which a set of inherent characteristics(3.5.1) fulfils requirements(3.1.2) NOTE1 The term "quality" can be used with adjectives as poor, good or excelent NOTE2 "Inherent ", as oposed to "assigned", means existing in something, especialy as a permanent characteristic"
- "Conformance to requirements" (Philip B. Crosby in the 1980s). The difficulty with this is that the requirements may not fully represent what the customer wants; Crosby treats this as a separate problem.
- "Fitness for use" (Joseph M. Juran). Fitness is defined by the customer.
- A two-dimensional model of quality (Noriaki Kano and others). The quality has two dimensions: "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 characterise this model more succinctly as: "Products and services that meet or exceed customers' expectations". One writer believes (without citation) that this is today the most used interpretation for the term quality.
- "Value to some person" (Gerald M. Weinberg)
- (W. Edwards Deming), "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. Better quality at lower price has a chance to capture a market. Cutting costs without improvement of quality is futile." "Quality and the Required Style of Management" 1988 See http://www.deming.org/
- "The loss a product imposes on society after it is shipped" (Genichi Taguchi). Taguchi's definition of quality is based on a more comprehensive view of the production system.
- Energy quality, associated with both the energy engineering of industrial systems and the qualitative differences in the trophic levels of an ecosystem.
- One key distinction to make is there are two common applications of the term Quality as form of activity or function within a business. One is Quality Assurance which is the "prevention of defects", such as the deployment of a Quality Management System and preventative activities like FMEA. The other is Quality Control which is the "detection of defects", most commonly associated with testing which takes place withn a Quality Management System typically referred to as Verification and Validation.
In engineering and manufacturing
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 dimensions of quality refer to the attributes that quality achieves in Operations Management
Quality supports dependability Dependability supports Speed Speed supports Flexibility Flexibility supports Cost. Quality <-> Dependability <-> Speed <-> Flexibility <-> Cost1
In the manufacturing industry it is commonly stated that “Quality drives productivity”. Improved productivity is a source of greater revenues, employment opportunities and technological advances. Most discussions of quality refer to a finished part, wherever it is in the process. Inspection, which is what quality insurance usually means, is historical, since the work is done. The best way to think about quality is in process control. If the process is under control, inspection is not necessary.--HalB
Please see these forum discussion threads where people present and discuss their definitions of what quality is. Discussions relating to the Definition of Quality: