There are many methods for quality improvement. These cover product improvement, process improvement and people based improvement. In the following list are methods of quality management and techniques that incorporate and drive quality improvement:
1. ISO 9004:2008 — guidelines for performance improvement.
2. ISO 15504-4: 2005 — information technology — process assessment — Part 4: Guidance on use for process improvement and process capability determination.
3. QFD — quality function deployment, also known as the house of quality approach.
4. Kaizen — 改善, Japanese for change for the better; the common English term is continuous improvement.
5. Zero Defect Program — created by NEC Corporation of Japan, based upon statistical process control and one of the inputs for the inventors of Six Sigma.
6. Six Sigma — 6σ, Six Sigma combines established methods such as statistical process control, design of experiments and FMEA in an overall framework.
7. PDCA — plan, do, check, act cycle for quality control purposes. (Six Sigma’s DMAIC method (define, measure, analyze, improve, control) may be viewed as a particular implementation of this.)
8. Quality circle — a group (people oriented) approach to improvement.
9. Taguchi methods — statistical oriented methods including quality robustness, quality loss function, and target specifications.
10. The Toyota Production System — reworked in the west into lean manufacturing.
11. Kansei Engineering — an approach that focuses on capturing customer emotional feedback about products to drive improvement.
12. TQM — total quality management is a management strategy aimed at embedding awareness of quality in all organizational processes. First promoted in Japan with the Deming prize which was adopted and adapted in USA as the Malcolm Baldrige National Quality Award and in Europe as the European Foundation for Quality Management award (each with their own variations).
13. TRIZ — meaning “theory of inventive problem solving”
14. BPR — business process reengineering, a management approach aiming at ‘clean slate’ improvements (That is, ignoring existing practices).
15. OQM — Object Oriented Quality Management, a model for quality management. 
Proponents of each approach have sought to improve them as well as apply them for small, medium and large gains. Simple one is Process Approach, which forms the basis of ISO 9001:2008 Quality Management System standard, duly driven from the ‘Eight principles of Quality managagement’, process approach being one of them. Thareja  writes about the mechanism and benefits: “The process (proficiency) may be limited in words, but not in its applicability. While it fulfills the criteria of all-round gains: in terms of the competencies augmented by the participants; the organisation seeks newer directions to the business success, the individual brand image of both the people and the organisation, in turn, goes up. The competencies which were hitherto rated as being smaller, are better recognized and now acclaimed to be more potent and fruitful “. The more complex Quality improvement tools are tailored for enterprise types not originally targeted. For example, Six Sigma was designed for manufacturing but has spread to service enterprises. Each of these approaches and methods has met with success but also with failures.
Some of the common differentiators between success and failure include commitment, knowledge and expertise to guide improvement, scope of change/improvement desired (Big Bang type changes tend to fail more often compared to smaller changes) and adaption to enterprise cultures. For example, quality circles do not work well in every enterprise (and are even discouraged by some managers), and relatively few TQM-participating enterprises have won the national quality awards.
There have been well publicized failures of BPR, as well as Six Sigma. Enterprises therefore need to consider carefully which quality improvement methods to adopt, and certainly should not adopt all those listed here.
It is important not to underestimate the people factors, such as culture, in selecting a quality improvement approach. Any improvement (change) takes time to implement, gain acceptance and stabilize as accepted practice. Improvement must allow pauses between implementing new changes so that the change is stabilized and assessed as a real improvement, before the next improvement is made (hence continual improvement, not continuous improvement).
Improvements that change the culture take longer as they have to overcome greater resistance to change. It is easier and often more effective to work within the existing cultural boundaries and make small improvements (that is Kaizen) than to make major transformational changes. Use of Kaizen in Japan was a major reason for the creation of Japanese industrial and economic strength.
On the other hand, transformational change works best when an enterprise faces a crisis and needs to make major changes in order to survive. In Japan, the land of Kaizen, Carlos Ghosn led a transformational change at Nissan Motor Company which was in a financial and operational crisis. Well organized quality improvement programs take all these factors into account when selecting the quality improvement methods.
 Quality standards
The International Organization for Standardization (ISO) created the Quality Management System (QMS) standards in 1987. They were the ISO 9000:1987 series of standards comprising ISO 9001:1987, ISO 9002:1987 and ISO 9003:1987; which were applicable in different types of industries, based on the type of activity or process: designing, production or service delivery.
The standards are reviewed every few years by the International Organization for Standardization. The version in 1994 was called the ISO 9000:1994 series; comprising of the ISO 9001:1994, 9002:1994 and 9003:1994 versions.
The last major revision was in the year 2008 and the series was called ISO 9000:2000 series. The ISO 9002 and 9003 standards were integrated into one single certifiable standard: ISO 9001:2008. After December 2003, organizations holding ISO 9002 or 9003 standards had to complete a transition to the new standard.
ISO released a minor revision, ISO 9001:2008 on 14 October 2008. It contains no new requirements. Many of the changes were to improve consistency in grammar, facilitating translation of the standard into other languages for use by over 950,000 certified organisations in the 175 countries (as at Dec 2007) that use the standard.
The ISO 9004:2000 document gives guidelines for performance improvement over and above the basic standard (ISO 9001:2000). This standard provides a measurement framework for improved quality management, similar to and based upon the measurement framework for process assessment.
The Quality Management System standards created by ISO are meant to certify the processes and the system of an organization, not the product or service itself. ISO 9000 standards do not certify the quality of the product or service.
In 2005 the International Organization for Standardization released a standard, ISO 22000, meant for the food industry. This standard covers the values and principles of ISO 9000 and the HACCP standards. It gives one single integrated standard for the food industry and is expected to become more popular in the coming years in such industry.
ISO has also released standards for other industries. For example Technical Standard TS 16949 defines requirements in addition to those in ISO 9001:2008 specifically for the automotive industry.
ISO has a number of standards that support quality management. One group describes processes (including ISO 12207 & ISO 15288) and another describes process assessment and improvement ISO 15504.
The Software Engineering Institute has its own process assessment and improvement methods, called CMMi (Capability Maturity Model — integrated) and IDEAL respectively.
 Quality software
The software used to track the three main components of quality management through the use of databases and/or charting applications.
 Quality terms
* Quality Improvement can be distinguished from Quality Control in that Quality Improvement is the purposeful change of a process to improve the reliability of achieving an outcome.
* Quality Control is the ongoing effort to maintain the integrity of a process to maintain the reliability of achieving an outcome.
* Quality Assurance is the planned or systematic actions necessary to provide enough confidence that a product or service will satisfy the given requirements.