Quality control

This article is about the project management process. For other uses, see Quality control (disambiguation).

Quality inspector in a Volkseigener Betrieb sewing machine parts factory in Dresden, East Germany, 1977.

X-ray zoom series of a network adapter card.

Quality control, or QC for short, is a process by which entities review the quality of all factors involved in production. ISO 9000 defines quality control as "A part of quality management focused on fulfilling quality requirements".

This approach places an emphasis on three aspects:

1. Elements such as controls, job management, defined and well managed processes, performance and integrity criteria, and identification of records
2. Competence, such as knowledge, skills, experience, and qualifications
3. Soft elements, such as personnel, integrity, confidence, organizational culture, motivation, team spirit, and quality relationships.

Controls include product inspection, where every product is examined visually, and often using a stereo microscope for fine detail before the product is sold into the external market. Inspectors will be provided with lists and descriptions of unacceptable product defects such as cracks or surface blemishes for example.

The quality of the outputs is at risk if any of these three aspects is deficient in any way.

Quality control emphasizes testing of products to uncover defects and reporting to management who make the decision to allow or deny product release, whereas quality assurance attempts to improve and stabilize production (and associated processes) to avoid, or at least minimize, issues which led to the defect(s) in the first place. For contract work, particularly work awarded by government agencies, quality control issues are among the top reasons for not renewing a contract.

Notable approaches to quality control

There is a tendency for individual consultants and organizations to name their own unique approaches to quality control—a few of these have ended up in widespread use:

Terminology	Approximate year of first use	Description
Statistical quality control (SQC)	1930s	The application of statistical methods (specifically control charts and acceptance sampling) to quality control.
Total quality control (TQC)	1956	Popularized by Armand V. Feigenbaum in a Harvard Business Review article and book of the same name. Stresses involvement of departments in addition to production (e.g., accounting, design, finance, human resources, marketing, purchasing, sales).
Statistical process control (SPC)	1960s	The use of control charts to monitor an individual industrial process and feed back performance to the operators responsible for that process. Inspired by control systems.
Company-wide quality control (CWQC)	1968	Japanese-style total quality control
Total Quality Management (TQM)	1985	Quality movement originating in the United States Department of Defense that uses (in part) the techniques of statistical quality control to drive continuous organizational improvement.
Six Sigma (6σ)	1986	Statistical quality control applied to business strategy. Originated by Motorola.

Quality control in project management

In project management, quality control requires the project manager and the project team to inspect the accomplished work to ensure its alignment with the project scope. In practice, projects typically have a dedicated quality control team which focuses on this area.

See also

• Analytical quality control
• Corrective and preventative action (CAPA)
• Eight dimensions of quality
• First article inspection (FAI)
• Good Automated Manufacturing Practice (GAMP)
• Good manufacturing practice
• Quality assurance
• Quality management framework
• Standard operating procedure (SOP)

References

•  This article incorporates public domain material from the General Services Administration document "Federal Standard 1037C" (in support of MIL-STD-188).

External links

• ASTM quality control standards