Quality Glossary - Q


QEDS Standards Group: The U.S. Standards Group on Quality, Environment, Dependability and Statistics consists of the members and leadership of organizations concerned with the development and effective use of generic and sector specific standards on quality control, assurance and management; environmental management systems and auditing, dependability and the application of statistical methods.

Q9000 series: Refers to ANSI/ISO/ASQ Q9000 series of standards, which is the verbatim American adoption of the 2000 edition of the ISO 9000 series standards.

QS-9000: Harmonized quality management system requirements developed by the Big Three automakers for the automotive sector. Replaced by Technical Specification 16949 effective Dec. 15, 2006. Also see “ISO/TS 16949.”

Qualitician: Someone who functions as both a quality practitioner and a quality technician.

Quality: A subjective term for which each person or sector has its 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. According to Joseph Juran, quality means “fitness for use;” according to Philip Crosby, it means “conformance to requirements.”

Quality assurance/quality control (QA/QC): Two terms that have many interpretations because of the multiple definitions for the words “assurance” and “control.” For example, “assurance” can mean the act of giving confidence, the state of being certain or the act of making certain; “control” can mean an evaluation to indicate needed corrective responses, the act of guiding or the state of a process in which the variability is attributable to a constant system of chance causes. (For a detailed discussion on the multiple definitions, see ANSI/ISO/ASQ A3534-2, Statistics—Vocabulary and Symbols—Statistical Quality Control.) One definition of quality assurance is: all the planned and systematic activities implemented within the quality system that can be demonstrated to provide confidence that a product or service will fulfill requirements for quality. One definition for quality control is: the operational techniques and activities used to fulfill requirements for quality. Often, however, “quality assurance” and “quality control” are used interchangeably, referring to the actions performed to ensure the quality of a product, service or process.

Quality audit: A systematic, independent examination and review to determine whether quality activities and related results comply with plans and whether these plans are implemented effectively and are suitable to achieve the objectives.

Quality circle: A quality improvement or self-improvement study group composed of a small number of employees (10 or fewer) and their supervisor. Quality circles originated in Japan, where they are called quality control circles.

Quality control: See “quality assurance/quality control.”

Quality costs: See “cost of poor quality.”

Quality engineering: The analysis of a manufacturing system at all stages to maximize the quality of the process itself and the products it produces.

Quality Excellence for Suppliers of Telecommunications (QuEST) Forum: A partnership of telecommunications suppliers and service providers. The QuEST Forum developed TL 9000 (see listing).

Quality function deployment (QFD): A structured method in which customer requirements are translated into appropriate technical requirements for each stage of product development and production. The QFD process is often referred to as listening to the voice of the customer.

Quality loss function: A parabolic approximation of the quality loss that occurs when a quality characteristic deviates from its target value. The quality loss function is expressed in monetary units: the cost of deviating from the target increases quadratically the farther the quality characteristic moves from the target. The formula used to compute the quality loss function depends on the type of quality characteristic being used. The quality loss function was first introduced in this form by Genichi Taguchi.

Quality management (QM): The application of a quality management system in managing a process to achieve maximum customer satisfaction at the lowest overall cost to the organization while continuing to improve the process.

Quality management system (QMS): A formalized system that documents the structure, responsibilities and procedures required to achieve effective quality management.

Quality plan: A document or set of documents that describe the standards, quality practices, resources and processes pertinent to a specific product, service or project.

Quality policy: An organization’s general statement of its beliefs about quality, how quality will come about and its expected result.

Quality rate: See “first pass yield.”

Quality score chart: A control chart for evaluating the stability of a process. The quality score is the weighted sum of the count of events of various classifications in which each classification is assigned a weight.

Quality tool: An instrument or technique to support and improve the activities of process quality management and improvement.

Quality trilogy: A three-pronged approach to managing for quality. The three legs are quality planning (developing the products and processes required to meet customer needs), quality control (meeting product and process goals) and quality improvement (achieving unprecedented levels of performance).

Queue time: The time a product spends in a line awaiting the next design, order processing or fabrication step.

Quick changeover: The ability to change tooling and fixtures rapidly (usually within minutes) so multiple products can be run on the same machine.

Quincunx: A tool that creates frequency distributions. Beads tumble over numerous horizontal rows of pins, which force the beads to the right or left. After a random journey, the beads are dropped into vertical slots. After many beads are dropped, a frequency distribution results. Quincunxes are often used in classrooms to simulate a manufacturing process. The quincunx was invented by English scientist Francis Galton in the 1890s.

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Basic Concepts