ASQ - Six Sigma Forum



C chart: See "count chart."

Calibration: The comparison of a measurement instrument or system of unverified accuracy to a measurement instrument or system of known accuracy to detect any variation from the required performance specification.

Capability analysis: The statistical comparison of the actual performance of a process with its specification limits. "Capable" systems perform completely within specification limits as established by customer requirements.

Capability Index

Capability index


Short or long term?

Includes shift and drift?

Considers process centering?


Short term




Short term




Long term




Long term








Capability maturity model: A framework that describes the key elements of an effective software process. It's an evolutionary improvement path from an immature process to a mature, disciplined process. The CMM covers practices for planning, engineering and managing software development and maintenance. When followed, these key practices improve the ability of organizations to meet goals for cost, schedule, functionality and product quality.

Cascading: The continuing flow of the quality message down to, not through, the next level of supervision until it reaches all workers. Same concept as "deploying."

Cause: An identified reason for the presence of a defect or problem.

Cause and effect diagram: A tool for analyzing process dispersion. It is also referred to as the "Ishikawa diagram," because Kaoru Ishikawa developed it, and the "fishbone diagram," because the complete diagram resembles a fish skeleton. The diagram illustrates the main causes and subcauses leading to an effect (symptom). The cause and effect diagram is one of the "seven tools of quality." (See listing).

Centerline: A line on a graph that represents the overall average (mean) operating level of the process.

Central tendency: The tendency of data gathered from a process to cluster toward a middle value somewhere between the high and low values of measurement.

Certification: The result of meeting the established criteria set by an accrediting or certificate granting organization.

Certified Quality Inspector (CQI): An ASQ certification.

Certified quality auditor (CQA): An ASQ certification.

Certified quality auditor (CQA)-biomedical: An ASQ certification.

Certified quality auditor (CQA)-hazard analysis and critical control point (HACCP): An ASQ certification.

Certified quality engineer (CQE): An ASQ certification.

Certified quality improvement associate (CQIA): An ASQ certification.

Certified quality manager: An ASQ certification.

Certified quality technician (CQT): An ASQ certification.

Certified reliability engineer (CRE): An ASQ certification.

Certified Six Sigma Black Belt (CSSBB): An ASQ certification.

Certified software quality engineer (CSQE): An ASQ certification.

Chain of customers: A philosophy that espouses the idea that each worker's "customer" is the next worker in the chain of people who produce a finished product or service.

Chain reaction: A chain of events described by W. Edwards Deming: improve quality, decrease costs, improve productivity, increase market with better quality and lower price, stay in business, provide jobs and provide more jobs.

Chain sampling plan: In acceptance sampling, a plan in which the criteria for acceptance and rejection apply to the cumulative sampling results for the current lot and one or more immediately preceding lots.

Champion: A business leader or senior manager who ensures that resources are available for training and projects, and who is involved in project tollgate reviews; also an executive who supports and addresses Six Sigma organizational issues.

Change agent: An individual from within or outside an organization who facilitates change within the organization. May or may not be the initiator of the change effort.

Change management: The process of bringing planned change to an organization. Change management usually means leading an organization through a series of steps to meet a defined goal.

Characteristic: The factors, elements or measures that define and differentiate a process, function, product, service or other entity.

Chart: A tool for organizing, summarizing and depicting data in graphic form.

Charter: A written commitment approved by management stating the scope of authority for an improvement project or team.

Checklist: A tool used to ensure all important steps or actions in an operation have been taken. Checklists contain items important or relevant to an issue or situation. Checklists are often confused with check sheets (see individual entry).

Check sheet: A simple data recording device. The check sheet is custom designed by the user, which allows him or her to readily interpret the results. The check sheet is one of the "seven tools of quality." (See listing). Check sheets are often confused with checklists (see individual entry).

Chi square tests: Compares actual data to expected results. The test verifies or rejects a null hypothesis, which assumes no significant difference between the actual and expected data.

Classification of defects: The listing of possible defects of a unit, classified according to their seriousness. Note: Commonly used classifications: class A, class B, class C, class D; or critical, major, minor and incidental; or critical, major and minor. Definitions of these classifications require careful preparation and tailoring to the product(s) being sampled to enable accurate assignment of a defect to the proper classification. A separate acceptance sampling plan is generally applied to each class of defects.

Closed-loop corrective action (CLCA): A sophisticated engineering system designed to document, verify and diagnose failures, recommend and initiate corrective action, provide follow-up and maintain comprehensive statistical records.

Code of conduct: Expectations of behavior mutually agreed on by a team.

Co-efficient of variation w/formula: The ratio of the standard deviation to the mean. Since the standard deviation and the mean of a data set have the same units, the coefficient of variation (denoted by CV) will be a unitless measure. CV=s/.

Collier, Simon (deceased): An ASQ president who led the Society during a critical growth period in 1952-53. His term was marked by numerous milestone events, including a membership increase of 22% and the formation of 11 new sections and the first divisions. Collier, an ASQ Honorary Member, was a chemist who began his career at the National Bureau of Standards (now the National Institute of Standards and Technology). Later he worked at Johns-Manville Corp., where he produced a quality training film used by more than 300 companies.

Common causes: Causes of variation that are inherent in a process over time. They affect every outcome of the process and everyone working in the process (see also "special causes").

Company culture: A system of values, beliefs and behaviors inherent in a company. To optimize business performance, top management must define and create the necessary culture.

Complaint tracking: Collecting data, disseminating data to appropriate persons for resolution, monitoring complaint resolution progress and communicating results.

Compliance: The state of an organization that meets prescribed specifications, contract terms, regulations or standards.

Computer aided design (CAD): Software used by architects, engineers, drafters and artists to create precision drawings or technical illustrations. CAD software can be used to create two-dimensional (2-D) drawings or three-dimensional (3-D) models.

Computer aided engineering (CAE): A broad term used by the electronic design automation industry for the use of computers to design, analyze and manufacture products and processes. CAE includes CAD (see listing) and computer aided manufacturing (CAM), which is the use of computers for managing manufacturing processes.

Concurrent engineering (CE): A way to reduce cost, improve quality and shrink cycle time by simplifying a product's system of life cycle tasks during the early concept stages.

Confidence interval, chi-square test: The probability valueassociated with a confidence interval. It is often expressed as a percentage.

Conflict resolution: The management of a conflict situation to arrive at a resolution satisfactory to all parties.

Conformance: An affirmative indication or judgment that a product or service has met the requirements of a relevant specification, contract or regulation.

Conformitè Europeënne Mark (CE Mark): Conformity European Union mark. The European Union created the CE Mark to regulate the goods sold within its borders. The mark represents a manufacturer's declaration products comply with the EU's New Approach Directives. These directives apply to any country that sells products within the EU.

Consensus: A state in which all the members of a group support an action or decision, even if some of them don't fully agree with it.

Consultant: An individual who has experience and expertise in applying tools and techniques to resolve process problems and who can advise and facilitate an organization's improvement efforts.

Consumer: The external customer to whom a product or service is ultimately delivered; Also called end user.

Consumer's risk: Pertains to sampling and the potential risk that bad product will be accepted and shipped to the consumer.

Continuous flow production: Means that items are produced and moved from one processing step to the next one piece at a time. Each process makes only the one piece that the next process needs, and the transfer batch size is one.

Continuous improvement (CI): Sometimes called continual improvement. The ongoing improvement of products, services or processes through incremental and breakthrough improvements.

Continuous process improvement (CPI): Provides a framework for organizations to make incremental process improvements, even in those processes that are considered to be in good operating condition. It is based on the philosophy that organizations can always make improvements.

Continuous quality improvement (CQI): A philosophy and attitude for analyzing capabilities and processes and improving them repeatedly to achieve the objective of customer satisfaction.

Continuous sampling plan: In acceptance sampling, a plan, intended for application to a continuous flow of individual units of product, that involves acceptance and rejection on a unit by unit basis and employs alternate periods of 100% inspection and sampling, the relative amount of 100% inspection depending on the quality of submitted product. Continuous sampling plans usually require that each t period of 100% inspection be continued until a specified number, i, of consecutively inspected units are found clear of defects. Note: For single level continuous sampling plans, a single d sampling rate (for example, inspect 1 unit in 5 or 1 unit in 10) is used during sampling. For multilevel continuous sampling plans, two or more sampling rates may be used: The rate at any time depends on the quality of submitted product.

Contrition: Forgiveness for error or mistake.

Control: State in which all special causes of variation have been removed from a process. Processes held in control are monitored, usually by means of a control chart, so that corrective action can be taken if special-cause variation returns.

Control chart: A chart with upper and lower control limits on which values of some statistical measure for a series of samples or subgroups are plotted. The chart frequently shows a central line to help detect a trend of plotted values toward either control limit.

Control limits: The natural boundaries of a process within specified confidence levels, expressed as the upper control limit (UCL) and the lower control limit (LCL).

Control plan (CP): A document that describes the required characteristics for the quality of a product or service, including measures and control methods.

Control process: A process involving gathering process data, analyzing process data, and using this information to make adjustments to the process.

Coordinate measuring machine (CMM): A device that dimensionally measures 3-D products, tools and components with an accuracy approaching 0.0001 in.

Corrective action: The implementation of solutions resulting in the reduction or elimination of an identified problem.

Corrective action recommendation (CAR): The full cycle corrective action tool that offers ease and simplicity for employee involvement in the corrective action/process improvement cycle.

Correlation (statistical): A measure of the relationship between two data sets of variables.

Cost of poor quality (COPQ): The costs associated with providing poor quality products or services. There are four categories of costs: internal failure costs (costs associated with defects found before the customer receives the product or service), external failure costs (costs associated with defects found after the customer receives the product or service), appraisal costs (costs incurred to determine the degree of conformance to quality requirements) and prevention costs (costs incurred to keep failure and appraisal costs to a minimum).

Cost of quality (COQ): A term coined by Philip Crosby referring to the cost of poor quality.

Cost savings vs. cost avoidance: Monetary objectives of improvement projects. Cost savings, recovering money lost due to quality problems, is usually the more urgent objective early in quality improvement programs. Cost avoidance, preventing future losses, becomes more important later in an implementation.

Cost/benefit analysis: Quantitatively evaluating the costs and benefits of a particular decision, program, project, or activity. Considering categories of benefits and costs, measuring them, and totaling their effects over time.

Count chart: A control chart for evaluating the stability of a process in terms of the count of events of a given classification occurring in a sample.

Count per unit chart: A control chart for evaluating the stability of a process in terms of the average count of events of a given classification per unit occurring in a sample.

Cp: Capability index used when analyzing a system's aptitude to perform. Measures the ability of a process to produce compliant products or services for a limited time. Also known as process entitlement.

Cpk : Capability index used when analyzing a system's aptitude to perform. Similar to Cp except that Cpk takes into account process centering.

Cpm: Capability index that takes into account variation between the process average and the target. If the process average and the target are the same value, Cpm will be the same as Cpk. If the average drifts from the target, Cpm will be less than Cpk.

Critical processes: Processes that present serious potential dangers to human life, health and the environment or that risk the loss of very large sums of money or customers.

Criticality: A term that refers to how often a failure will occur, how easy it is to diagnose, and whether it can be fixed.

Crosby, Philip (deceased): The founder and chairman of the board of Career IV, an executive management consulting firm. Crosby also founded Philip Crosby Associates Inc. and the Quality College. He wrote many books including Quality Is Free, Quality Without Tears, Let's Talk Quality, and Leading: The Art of Becoming an Executive. Crosby, who originated the zero defects concept, was an ASQ Honorary Member and past president.

Cross functional: A term used to describe a process or an activity that crosses the boundary between functions. A cross functional team consists of individuals from more than one organizational unit or function.

Cross pilot: See "scatter diagram."

CTQs: Element of a process or practice that has a direct impact on its perceived quality. (Steve Littleton) -or- The measurable characteristics of a product or process that are crucial to customer satisfaction.

Cultural resistance: A form of resistance based on opposition to the possible social and organizational consequences associated with change.

Culture change: A major shift in the attitudes, norms, sentiments, beliefs, values, operating principles and behavior of an organization.

Culture, organizational: A common set of values, beliefs, attitudes, perceptions and accepted behaviors shared by individuals within an organization.

Cumulative sum control chart (CUSUM): A control chart on which the plotted value is the cumulative sum of deviations of successive samples from a target value. The ordinate of each plotted point represents the algebraic sum of the previous ordinate and the most recent deviations from the target.

Current good manufacturing practices (CGMP): Regulations enforced by the U.S. Food and Drug Administration for food and chemical manufacturers and packagers.

Customer: See "external customer" and "internal customer."

Customer co-production: The participation of a customer in the delivery of a service product. For example, in many restaurants it is not uncommon for customers to fill their own drinks.

Customer delight: The result of delivering a product or service that exceeds customer expectations.

Customer needs, expectations: Needs, as defined by customers, which meet their basic requirements and standards. (Steve Littleton)

Customer rationalization: The process of reaching an agreement between marketing and operations as to which customers add the greatest advantage and profits over time.

Customer relationship management (CRM): A strategy used to learn more about customers' needs and behaviors to develop stronger relationships with them. It brings together information about customers, sales, marketing effectiveness, responsiveness and market trends. It helps businesses use technology and human resources to gain insight into the behavior of customers and the value of those customers.

Customer satisfaction (CS): The result of delivering a product or service that meets customer requirements.

Customer-supplier model (CSM): A model depicting inputs flowing into a work process that, in turn, add value and produce outputs delivered to a customer. Also called customer-supplier methodology.

Customer supplier partnership: A long-term relationship between a buyer and supplier characterized by teamwork and mutual confidence. The supplier is considered an extension of the buyer's organization. The partnership is based on several commitments. The buyer provides long-term contracts and uses fewer suppliers. The supplier implements quality assurance processes so incoming inspection can be minimized. The supplier also helps the buyer reduce costs and improve product and process designs.

Cycle time: The elapsed time between the start and completion of a task or an entire process; for example, in order processing it can be the time between receipt and delivery of an order.

Cycle time reduction: Speeding up the time it takes to complete a process from start to finish.

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