A measure of variation within a dataset, representing the difference between the highest and lowest values in the data.

A control chart used in quality control to monitor and assess the variability or dispersion of a process over time using range measurements.

A statistical measure indicating the proportion of variation in a dependent variable explained by an independent variable in regression analysis.

A modified version of R-squared in regression analysis, adjusted for the number of predictors, providing a better fit assessment.

The proportion of variation in a dependent variable predicted or explained by an independent variable in regression analysis.

Repeatability and Reproducibility: A measure evaluating the consistency and agreement among different appraisers or equipment in measurements.

Responsible, Accountable, Consulted, Informed: A framework delineating roles and responsibilities within a project or process.

A method utilizing RACI charts to identify and clarify roles and responsibilities among stakeholders in a project or process.

Method to assess an organization‘s maturity level. RADAR stands for Results, Approach, Deployment, Assessment and Refine. It belongs to the model prepared by the EFQM which is used to assess an organization‘s progress towards the achievement of excellent results. The assessment method is based on relevance and usability, the Results, the Approach that leads to them, the degree of Deployment and the Assessment and Refinement (EFQM Excellence Model 2010). The individual assessments of the 32 sub-criteria can be combined into a total assessment between 0 and 1000 points.

A unit of measurement for angles, representing an angle subtended by an arc equal in length to the radius of the circle.

Deutsches Institut für Gütesicherung und Kennzeichnung e.V., Sankt Augustin. Non-profit institution founded in 1925 under the name Reichs-Ausschuss für Lieferbedingungen (RAL – Imperial Commission for Delivery Terms and Quality Assurance). Today its fundamental functions are: creating quality marks, delivering globally binding color references, awarding the “Blue Angel” environmental label and the European eco label, registrations, agreements, and RAL attestations. www.ral.de

RAM: Reliability/availability/maintainability (see individual entries).

Random cause: A cause of variation due to chance and not assignable to any factor.

Non-controllable, random deviation of the measurement result from the expectation. (On the basis of DIN 1319-1)

A subset of individuals or items drawn from a larger population in a manner that ensures each member has an equal chance of being selected.

Random sampling: A commonly used sampling technique in which sample units are selected so all combinations of n units under consideration have an equal chance of being selected as the sample.

A variable whose value is determined by chance or probability, with possible outcomes subject to randomness.

Creativity technique in which ideas are derived from randomly selected words (or images). The random element is used to produce completely new associations and ideas. Procedure: First a word is selected from a random source that has nothing to do with the initial problem (for example, a random word from the dictionary). This word is used as a stimulus for a solution. In the next step, all participants note what this word brings to mind (brainstorming). Then the noted ideas are analyzed and applied to the starting problem.

The process of assigning subjects or items to different groups or treatments randomly, reducing bias and ensuring equal distribution.

Difference between the largest individual actual value and the smallest individual actual value. (On the basis of DGQ Volume 11-04:2012)

Range (statistical): The measure of dispersion in a data set (the difference between the highest and lowest values).

Range chart (R chart): A control chart in which the subgroup range, R, evaluates the stability of the variability within a process.

A position or level of importance assigned to an item, variable, or individual in relation to others within a specific context or dataset.

A focused and time-bound event involving cross-functional teams to rapidly identify and implement improvements in a specific process or area.

The percentage or ratio of time a system or asset is available and operational compared to the total available time within a specific period.

The speed, efficiency, or output level achieved by a system, process, or individual, often measured against established standards or benchmarks.

The level or proportion of defect-free products or services produced within a system or process, indicating the quality performance rate.

Effects or impacts resulting from changes in ratios or proportions of variables or factors within a system or model, context-dependent.

Residuals in statistical analysis specifically related to ratios, potentially indicating deviations or discrepancies in ratio-related models.

Reliability-Centered Maintenance: A maintenance strategy focusing on optimizing maintenance efforts based on the criticality of assets or systems.

Re-engineering: A process for restructuring an entire organization and its processes.

Recall: The act of officially summoning someone or something back to its place of origin.

Quality inspection for accepting a product. The customer (further processor, dealer or end customer), the client or a representative body conducts the receiving inspection. (On the basis of DIN 55350-17)

Renewed certification. Before a certificate expires, a re-certification can be performed. Certificates for management systems are usually valid for three years. See also: Repeat audit.

Evaluation of an audit finding. Example: A required procedure of a normative requirement is completely fulfilled, or a required procedure is completely installed in the company. Planning, performance of the planned activities, and effectiveness of the activities can be proven. The recommendation points out a potential for increasing the effectiveness. A corrective action is not absolutely required, and the issuing or maintenance of a certificate is also not called into question. Recommended actions can be carried out.

1. Verification document that reflects a situation (e.g., after an activity has been carried out) or an achieved result at a specific time. (On the basis of ISO 9000:2015)

Red bead experiment: An exercise developed by W. Edwards Deming to illustrate that results are largely dependent on the management system—which is owned by top management—and not the employees who work in the system

Concept from the Six Sigma methodology. It describes the core factors that influence a process. These are identified and optimally adjusted in the Six Sigma DMAIC project management phases. The objective is to increase the process capability.

See Business process reengineering.

Fixed ranges for permissible values of influencing factors. The ranges are defined by target values with limiting values or tolerance zones. (On the basis of DIN 1319-1)

A line or marker used as a benchmark or reference point in graphs, charts, or diagrams to denote specific thresholds, targets, or averages.

Measurement standard with the highest locally available precision. The measurement made there is derived from this measurement standard (reference). (On the basis of DIN 1319-1)

Material or substance with characteristics whose values are fixed with sufficient precision and time dependency. These refer to the calibration, evaluation of a measurement procedure or quantitative determination of a material‘s characteristic values. (On the basis of DIN 1319-1)

(Process) model to structure/prepare the processes in a company that is typical for the sector and that has a certain degree of general validity.

Stipulated procedure used to determine a sequence of characteristic values of a continuous characteristic that is valid on the basis of an agreement. (DGQ Volume 11-04:2009)

A specific value used as a standard, benchmark, or point of comparison within a dataset or process for evaluating performance or outcomes.

Registrar: Generally accepted equivalent term for “certification body.”

Registration: The act of including an organization, product, service or process in a compilation of those having the same or similar attributes.

Registration to standards: A process in which an accredited, independent third-party organization conducts an on-site audit of an organization's operations against the requirements of the standard to which the organization wants to be registered. Upon successful completion of the audit, the organization receives a certificate indicating it has met the standard requirements. In countries outside the United States, this generally is known as certification.

Assignment of a nonconforming product into a different grade with the objective of satisfying the requirements that could not be fulfilled in the original grade due to a deviation from the required specification. (On the basis of ISO 9000:2015)

Statistical model for the quantitative description of a correlation between an input variable and an output variable. A regression function describes the model, and a regression line, for example, shows it graphically. There are simple, multiple, linear and nonlinear regressions.

Regression analysis: A statistical technique for determining the best mathematical expression describing the functional relationship between one response and one or more independent variables.

The order or complexity of a regression model, indicating the number of predictors or terms used in the model to predict the response variable.

Regulatory body for the telecommunication and postal sectors in Germany. The organization was founded on January 1, 1998 and renamed as the Bundesnetzagentur on July 13, 2005. See BNetzA.

A document that has binding, statutory stipulations and that is prepared by a public authority. (On the basis of DIN 45020-21)

See EMAS. This regulation replaces Regulation (EC) No. 761/2001 and entered into force on January 11, 2010.

See EMAS. This regulation was repealed by Regulation (EC) No. 1221/2009 from November 25, 2009.

Nonconforming product that can no longer be used for the originally intended purpose and that should be disposed of. The disposal can be in the form of recycling, destruction or scrapping. Nonconforming products that, for example, are not reworked because of cost considerations, are likewise rejects. (On the basis of DIN 55350-11)

The level of defects or quality issues within a product or process that can still be accepted or tolerated without causing significant concerns.

Rejection number: The smallest number of defectives (or defects) in the sample or samples under consideration that will require rejection of the lot.

Relations diagram: See "interrelations diagram."

You can find out more about this in the Quality management principles.

The position or ranking of an item, variable, or entity concerning others, often expressed in terms of higher or lower position within a context.

Approval for the next step in a process. In conjunction with software, the word “release“ often refers to the version of the software. (On the basis of ISO 9000:2015)

Reliability: The probability of a product performing its intended function under stated conditions without failure for a given period of time.

A plan outlining the procedures, criteria, and methodologies used to assess the reliability and durability of systems, products, or processes.

Location that is not the site of any production processes but that supports production sites. (On the basis of IATF 16949:2016)

Action taken on a nonconforming product in order to make it acceptable for the intended use. Repairs also include remedial actions taken on a product that is now nonconforming but that was previously conforming in order to restore it for use (for example, as part of maintenance). A repair can affect or change parts of the nonconforming product, unlike rework. (On the basis of ISO 9000:2015)

A system or asset that can be repaired or restored to its operational state after failure or breakdown, typically through maintenance activities.

Audit that is conducted before the validity of the certificate has expired in order to verify the effectiveness of the quality management system and its conformity with the standard with respect to the certifier again. See also Recertification.

Quality inspection that takes place when an undesirable result was determined on a unit (same type or on the improved unit) in a previous, authorized quality inspection. (On the basis of DIN 55350-17)

Repeatability: The variation in measurements obtained when one measurement device is used several times by the same person to measure the same characteristic on the same product.

The time required to restock or refill inventory, materials, or resources to maintain the desired or optimal levels within a system or process.

Duplicate or multiple observations or experiments performed under similar conditions to ensure consistency or validate results.

The process of repeating or duplicating experiments, studies, or observations to validate findings, enhance reliability, or confirm consistency.

Potentially a specific software tool, application, or platform used for generating or creating reports, context-dependent.

Reproducibility: The variation in measurements made by different people using the same measuring device to measure the same characteristic on the same product.

The amount of waste considered necessary or unavoidable within a process or system due to inherent constraints or limitations.

Expectation or need that is specified, usually assumed or obligatory. (On the basis of ISO 9000:2015)

Rough concept that describes the requirements, expectations and wishes for a planned product.

Requirements: A need or expectation, generally mandatory or compulsory.

Graphical representations displaying the residuals or differences between observed and predicted values against predictor variables in regression analysis.

Deviations or differences between observed and predicted values in statistical analysis, indicating the model's error or unexplained variance.

Residuals specifically related to orthogonal regression analysis, representing unexplained variability or error within the regression model.

Measure of the distance between neighboring measured values that a measuring instrument can still unambiguously distinguish. (On the basis of DIN 1319-1)

A calendar or schedule indicating the availability, allocation, or planned usage of resources such as manpower, equipment, or facilities.

The process of adjusting resource allocation or schedules to optimize resource utilization, preventing overloading or underutilization.

Resource utilization: Using a resource in a way that increases throughput.

Variables used in statistical models, where predictor variables predict or explain changes in response variables in regression or modeling analyses.

The process of fine-tuning or optimizing responses or outcomes within a system or process to achieve desired performance or efficiency levels.

An experimental design methodology used to model and optimize the relationship between multiple variables and a response in a complex system.

Part of competence that specifies which activities are to be carried out.

Depiction of all necessary process details. The flow is divided in such a way that all process steps that belong to a person, department or company (or sphere of responsibility) are drawn in a separate area of the diagram. It is particularly well-suited to visualize problems that are based on structural causes.

This global initiative stands for the chemical industry‘s intention to strive for the continuous improvement of the companies in the areas of the environment, safety and health (independently of statutory provisions) and also to report the progress to the public on a regular basis.

Terms referring to constraints or limitations (restricted) and absence of limitations or freedom (unrestricted) within a specific context.

Characteristic value that is ascertained by determination. Depending on the type of determination, the result of determination can be called the assessment result, observation result, measurement result, calculation result or statistical estimation result. It can refer to any type of characteristic. (On the basis of DIN 55350-12)

Results: Outcomes that can be qualitative or quantitative.

An analysis or examination conducted after an event or project, focusing on evaluating outcomes, lessons learned, or performance retrospectively.

Products or items sent back or refunded to a manufacturer or seller due to defects, damages, customer dissatisfaction, or other issues.

1. Activity to determine if an object is suitable, adequate and effective for achieving established objectives, e.g., management review, design and development review, review of customer requirements or review of corrective actions. (On the basis of ISO 9000:2015)

Method to review the development quality. With the help of a questionnaire, the project or product is technically and organizationally analyzed and critically judged. The military sector developed the review technique method in the mid-1960s.

Plans or strategies detailing modifications, updates, or changes to existing processes, products, or systems based on identified needs or improvements.

Action taken on a nonconforming product so that it can still satisfy the requirements. Rework does not affect or change parts of the nonconforming product; repair can affect or change parts of the nonconforming product. (On the basis of ISO 9000:2015)

A repetitive cycle involving reworking or revisiting processes or products to address quality issues or defects until satisfactory standards are met.

Rapid Improvement Event: See Rapid Improvement Event.

Right size: Matching tooling and equipment to the job and space requirements of lean production. Right sizing is a process that challenges the complexity of equipment by examining how equipment fits into an overall vision for workflow through a factory. When possible, right sizing favors smaller, dedicated machines rather than large, multipurpose batch processing ones.

Right the first time: Meeting specified requirements with the initial attempt.

Consequence (effect) of uncertainty. Uncertainty is characterized by a lack of information or knowledge with respect to an event, its consequences or probability. Any deviation from expectations (either positive or negative) is called an effect. (On the basis of ISO 9000:2015)

Risk management: The identification, evaluation and prioritization of risks to eliminate or mitigate their probability or severity or to leverage opportunities.

This value can be used to help quantify potential failures (nonconformities) for risk assessment (in the framework of the FMEA). The risk priority number (RPN) is calculated as follows:

Robustness: The condition of a product or process design that remains relatively stable, with a minimum of variation, even though factors that influence operations or usage, such as environment and wear, are constantly changing.

The probability or measure of the total output or yield of a multi-step process, considering all potential points of failure or defects.

Root cause: A factor that caused a nonconformance and should be addressed with corrective action.

Root cause analysis: The method of identifying the cause of a problem, solving it and preventing it from occurring again. Uncovering the correct and accurate reason(s) why something is happening or has already occurred.

A proposed explanation or assumption regarding the fundamental cause or origin of a problem, guiding investigation and problem-solving efforts.

A mathematical operation to approximate a number to a specified decimal place or significant figure, typically based on specific rounding rules.

See Risk priority number.

A mnemonic or acronym used to define criteria or expectations: Reasonable, Understandable, Measurable, Believable, Achievable.

Run chart: A chart showing a line connecting numerous data points collected from a process running over time.

A visual display representing data points plotted against time or sequential order to observe patterns, trends, or shifts in a process or system.

Runner: A person on the production floor who paces the entire value stream through the pickup and delivery of materials through kanban (see listing) usage.

Experimental design methodology used to analyze the effects of sequence or order in an experiment.