Quality
From Wikipedia, the free encyclopedia
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
- In physics, the range of frequencies over which something will characteristically respond.
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. Aristotelian) 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.
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[edit] In Business, Engineering & Manufacturing
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:
- "Degree to which a set of inherent characteristic fulfills requirements" as ISO 9000
- "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 characterize 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 within a Quality Management System typically referred to as Verification and Validation.
However, the American Society for Quality defines "quality" as "a subjective term for which each person has his or her own definition.In technical usage, quality can have two meanings: 1. the characteristics of a product or service that bear on its ability to satisfy stated or implied needs. 2. a product or service free of deficiencies. " Source: http://www.asq.org/glossary/q.html
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.
[edit] In music
In music quality refers primarily to the timbre, but also dynamics and musical texture, of a section or piece.
[edit] In phonetics
In phonetics quality refers to the articulatory features that distinguish vowels and to their acoustic correspondent. Vowel quality is opposed to vowel quantity.
[edit] In philosophy
Robert M. Pirsig, in his book Zen and the Art of Motorcycle Maintenance, studies the philosophical aspects of Quality, and examines the distinctions and relationship between classical and romantic quality, seeking to reconcile the two views and understand how they stand in relationship to each other.
In this context the two aspects of classical object-oriented and romantic subject-oriented quality roughly parallel aesthetic quality and functional quality. The resolution of the book points to a view of quality which relegates this subject-object dualism to a product of a non-dualistic Absolute.
[edit] In Physics
The quality of heat may be used to describe the availability of thermal energy as dictated by the second law of thermodynamics. Also see Exergy efficiency.
Furthermore, in response theory|, the quality of an excited system is related to the number of excitation frequencies to which it can respond. In the case of a homogeneous, isotropic system, the quality is proportional to the FWHM.
This sense of the phrase is the primogenitor of the usage of the word in music; there it is a measure of the number of harmonics of a fundamental frequency of an instrument (the higher the quality, the richer the sound).
[edit] See also
- Quality Management System
- Quality control
- W. Edwards Deming
- Six Sigma
- Total Quality Management
- Theory of Constraints
- ISO 9000
- Metaphysics of Quality from Zen and the Art of Motorcycle Maintenance and Lila: An Inquiry into Morals by Robert M. Pirsig
- Software quality
- Video quality
- Energy quality
