Technical terms of quality management: S



Safety exists in a company or organization when the probability that there will be personal injury or material damage or a disruption of operating sequences is contained to an acceptable level. The classical areas of safety (occupational health and safety as the freedom from danger at the workplace; operational safety as trouble-free functioning of technical systems; building safety in the sense of functioning surveillance) are joined today particularly by information technology (IT) safety.


Safety management

All planning, actions or procedures that guarantee the safety of a company or organization and that are intended to limit effects and repercussions in the event that a disturbance occurs. The functions include threat and weak point analyses, formulation of safety objectives and actions, preparation of a safety concept and the specification of responsibilities in all areas. Safety management furthermore includes reviewing the safety concept implementation, performance of the planned actions, compliance with safety guidelines, and the effectiveness of the implemented safety actions.


Safety management system

Procedures and processes to prevent breakdowns and to limit their effects. A safety management system regulates the following aspects: Organization and personnel; determination and evaluation of the risks of breakdowns; monitoring of the operation; safe performance of changes; planning for emergencies; monitoring the safety management system performance; and systematic examination and review.



  1. Material unit on which, for some special reason, a quality inspection is conducted or that is required in the framework of a quality inspection. (On the basis of DIN 55350-15)
  2. One or more units that are taken from the population or from a part of the population. Often the characteristic values that were determined in the units are called the sample instead of the units of samples. Therefore the number of the characteristic values and the number of sample units can be different. The purpose of a sample is to acquire knowledge about a population or about a subpopulation. The population can be an inspection lot, for example. (On the basis of DIN 55350-14)

Sample inspection

When a sample is subjected to a quality inspection. (On the basis of DIN 55350-17)


Sample variance

Sum of the squares of the deviations of the actual values from their arithmetic mean divided by one less than the number of actual values.
(DGQ Volume 11-04:2009)


Sampling plan

Specification of the increments to be taken, samples to be constituted and measurements to be made. (On the basis of ISO 3534-2)


Sampling scheme

Combines sampling plans with sampling purposes. (On the basis of ISO 3534-2)


Sampling size

Number of units that are withdrawn for a sample. Often the characteristic values found in the units are called a sample instead of the units of the sample. This can result in confusion with regard to the sampling size. Ultimately the number of the characteristic values and the number of sample units can be different. (On the basis of DIN 55350-14)



Swiss Association for Quality, Kirchberg (Switzerland).


Scatter diagram

Also called correlation diagram. Correlations are relationships between factors or variables that are determined with statistical methods. The simplest correlation is positive linearity (if X increases by 1, Y also increases by 1). The graphical representation of a correlation is called a scatter diagram, or correlation diagram (Q7). The variable or factor values are shown on an X and Y axis with points in the diagram and a line is drawn to connect them. The course of the line provides information about the type of correlation (positive, negative, linear, exponential, etc.) Correlations are not to be confused with causal links.



Safety Certificate for Contractors. Requirements for safety, health and environmental management systems. Standard developed by the Dutch mineral oil and petroleum industry in 1989. The objective was to place uniform requirement criteria on the contractor‘s safety management when awarding contracts for maintenance and installation work and construction projects.



See Supply chain management.


Scoring model

See EFQM Excellence Award.



See Supply chain quality.



Action on a nonconforming product with the objective of precluding its originally intended use (e.g., by recycling, destruction). In the case of a nonconforming service situation, use is precluded by discontinuing the (provision of the) service. (On the basis of ISO 9000:2015)


Screening inspection

100% inspection in which all units that are found to be nonconforming are sorted out.
(DGQ Volume 11-04:2009)


Second-party audits

Second-party audits are audits conducted by the customer or on behalf of the customer (supplier audits). Second-party audits are external audits. (On the basis of ISO 9000:2015)


Secondary nonconformity

See Finding.



Personal sense of order. Each employee must maintain high standards of housekeeping and workplace organization at all times. Cleanliness and order should become a habit. Japanese term, see also 5S.



Set in order. This Japanese term means that only the work materials that are actually needed should be at the workplace. Nonessential tools and machines, defective parts and unnecessary papers and documents should be removed from the workplace so as to bring about order. See also: 5S.



Shine or sanitize (cleanliness). Workplace, machines and tools must be kept clean. Japanese term, see also 5S.



Straighten (tidiness). In order to maintain order at the workplace, the necessary work materials must be in perfect condition. Furthermore, they should be either readily available or kept at the right place. Japanese term, see also 5S.



Comprehensive and systematic review of the organization’s activities. These refer to the quality management system or to an excellence model. Self-assessment can give the organization an overall view of its performance and the degree of maturity of its quality management system. (On the basis of DIN 9000:2015)



Also Supplier‘s declaration or vendor declaration Written declaration given by a supplier according to a defined procedure that indicates that a unit that it is to supply, but that has not yet been realized, will fulfill the quality requirements, or that a unit that has already been realized fulfils the quality requirements, or that both statements are true.
(DGQ Volume 11-04:2009)


Semi-autonomous work group

With a view to a common objective, members of a group produce or complete products or services on their own responsibility and according to their own planning. This requires a certain level of autonomy. The individual groups are conceded the freedom needed to act and make decisions independently.



Change in the measured value of the quantity output by a measuring instrument relative to the change in the input quantity that caused it. (On the basis of DIN 1319-1:1195)



An organization’s (process) output, where at least one activity must be performed between organization and customer. A service’s essential elements are mostly intangible in nature, with software being a prime example, since information is at its core, regardless of the medium. As a rule, a service includes activities at the interface with the customer and is directly experienced by the customer. (On the basis of ISO 9000:2015)


Seven wastes

See Muda.



Experimental design technique that was named after its creator Dorian Shainin (1914-2000). Shainin developed a strategy to solve problems which, like the Pareto rule, assumes that a multitude of problems are associated with only a few causes.


Shainin method

See Design of experiments.



Stockholder, financier, investor in a company.


SHE management system

Safety, health, environmental management system. See also: SCC.


Shewhart quality control chart

See Quality control chart.



Sustain (discipline). There must be compliance with standards, rules and regulations that concern the work process. Japanese term, see also 5S.


Sigma value

The sigma value provides information about the process capability. With a normal distribution, the sigma value indicates how many standard deviations there are from the average value to the next (customer) specification limit. The sigma value (called the z value in mathematics) can be calculated for both qualitative and quantitative data. The sigma values can make it possible to compare different processes because they compare the processes by looking at their dispersion with regard to the customer requirements, or by looking at the capability of the process to fulfill the customer requirements.


Simultaneous engineering

Special form of project organization during product development in order to shorten the development time. When developing products, the individual steps are worked off in parallel, not sequentially. This results in simultaneous or overlapping product development stages. Suppliers and system manufacturers are included in this process at an early point in time and to a large extent.


Single sourcing

Concentration of the procurement on a few system suppliers, i.e., suppliers who offer many products or services from one source.



Supplier – Input – Process – Output – Customer.
Process depiction that already shows correlations in the entire chain between supplier and customer, particularly whether or not the outputs actually offer what the customer wants.


Six Sigma

Six Sigma fundamentally has two meanings: On the one hand, six sigma is a statistical measurand for process capability and consequently a measurand for the quality of a process with regard to fulfilling customer requirements. 6 Sigma process capability means that the specification limits are 6 standard deviations, or 6 sigma, removed from the average value. If this process capability has been reached then there are only 3.4 defective parts in 1 million possibilities. On the other hand, the term Six Sigma also refers to a corporate strategy. The strategy starts with the customer expectations and aims at optimizing all of a company‘s processes and ultimately increasing the profit. Key people are the Champion, the Master Black Belt, the Black Belt, the Green Belt and the Yellow Belt. (Also see each term). The Six Sigma method was created in 1979 when enormous quality problems at Motorola led to a search for methods for product and process improvement.



Service level agreement: Interface agreement for the provision of services. An SLA governs the cooperation between an (internal or external) customer and an (internal or external) service provider with a view to the type, scope and cost of the services to be provided.



Small and medium sized enterprises.



Society of Motor Manufacturers and Traders Ltd., London. www.smmt.co.uk



Schweizerische Normen-Vereinigung [Swiss Association for Standardization], Winterthur, Switzerland. www.snv.ch



Social environment in which an organization operates.
Remark 1: In the narrower sense, society refers to those people who live in the immediate surroundings of the production facilities or equipment for realizing material and immaterial products by the considered organization.
Remark 2: In the broader sense, the term society comprises the entire human society as the activities of organizations can be effective beyond borders.
(DGQ Volume 11-04:2009)



See Product.



= Standard Operating Procedure
Work instruction that describes and documents recurring work sequences.



See Statistical Process Control.


Special characteristics

Product characteristics or production process parameters. These can affect safety, compliance with regulatory demands, fit, function, performance or further processing of the product. (On the basis of IATF 16949:2016)


Special process

Process in which the quality inspections either cannot determine the result with regard to quality, cannot determine it completely, can only determine at a disproportionately high expenditure or cannot determine it on time. In principle, special processes are therefore qualified ahead of time and monitored. (On the basis of DIN 55350-11)



Document with specified requirements for a product. A specification can concern activities (e.g., procedure document, process specification or test specification) or products (e.g. product specification, performance specification or drawing). (On the basis of ISO 9000:2015)


Specification limit

In its requirements for a product or service, the customer specifies a desired value that should be achieved. The customer additionally specifies specification limits that show the tolerated fluctuations. This results in a lower tolerance limit, also called lower specification limit (LSL) and an upper tolerance limit, also called upper specification limit (USL).



Strategic Planning Institute. See PIMS study.



Safety Quality Assessment System. Standard from the European Chemical Industry Council CEFIC. Quality, safety, occupational health and safety, and environmental management system for service providers in the logistics and chemical sectors with the objective of a uniform evaluation by independent assessors who use the same standard/questionnaire.



Statistical quality control.



See Interested party.



NATO Standardization Agreement: Standardization agreement involving NATO member countries on the use of standardized procedures or similar equipment. The objective is to achieve the most standardized equipment for all NATO troops possible in various areas.



Uniform, recognized and applied method to produce or perform something. A standard has the form of a formalized or non-formalized set of rules or of a specification. Technical areas have industry standards, manufacturer-specific standards and the open standard.


Standard deviation

A statistical measure of dispersion that is based on the square of the deviation of the individual values from the average.


Standard value

Measured value or numerical value that must be met or reached without the stipulation of concrete limiting values. (On the basis of DIN 55350-12)



Harmonization of measures, types and procedural methods.


Standards organization

The task of a national standards organization is to determine the necessity of a planned standard, as well as its requirements and contents. These are subsequently stipulated and published as a national standard. The standardization work in Germany is organized in standardization committees and work groups within the DIN. Representatives from business, science, the state and interested parties cooperate on working out standards. In Germany, industry-wide standardization is the task of the business sector‘s self-regulation. The DIN is a member of CEN, whose main task is to develop European standards. The ISO is responsible for international standardization; it unites the national standards organizations around the world.



Condition of a unit at a particular point in time of the observation. (On the basis of DIN 40041:1990)


Statistical methods

Statistical methods that are used for statistical process control are, for example, control charts to check and monitor process stability or process capability analyses.


Statistical Process Control

Statistical quality control for processes (DGQ Volume 11-04:2009). Tool based on fundamental mathematical and statistical principles. It is used to stabilize an optimized process by means of constant monitoring and, where applicable, corrections in this optimized state. The tool was developed by the American Shewhart.


Statistical quality control

Part of quality control with the use of statistical procedures. (On the basis of DIN 55350-11)


Statistical quality inspection

Quality inspection using statistical methods. (On the basis of DIN 55350-17)



Plan to achieve long-term or overall objectives. (On the basis of ISO 9000:2015)



Separate representation of data with different conditions. The population is broken down into the most homogenous parts possible and then samples are drawn from these parts. If the population is inhomogeneous, this makes the overall sample representative.


Structural organization

An organization’s hierarchical framework or structure. The structural organization regulates responsibilities, work assignments and resource allocation. The structural organization includes the company hierarchy (shown, for example, in an organizational chart), the structure of the areas or departments, the job plan, the geographic distribution (locations, branches) and the relationship to affiliated companies such as subsidiaries, parent company or partner firms. Together, the structural organizational and process organization form the business or company organization.



Subset of a population. (On the basis of DIN 55350-14)



Subdivision of core, support or management processes or a combination of activities. Several subprocesses form a main process.


Suggestion plan

See Employee suggestion plan.



An organization or person who supplies a product. A supplier can belong to the organization (internal supplier) or can be someone outside the organization (external supplier). Sometimes the term “contractor“ is used if the situation involves a contract. Examples of suppliers given by ISO 9000:2015 are also producers, distributors, retailers, vendors of a product or provider or a service or provider of information. (On the basis of ISO 9000:2015)


Supplier audit

Quality audit by the customer and a means for rating suppliers. See Second-party audit.


Supplier evaluation

Evaluation of a supplier‘s performance by the client. Quality management systems offer various procedures for supplier evaluation.

  • Before the order is placed: Gathering information that reflects the supplier‘s ability, e.g., by means of an audit;
  • After the order is placed: Monitoring of the supplier‘s quality management system by the client, a representative of the client or an independent organization (supplier audit), review of the offered product at the supplier by the client or by a representative of the client and/or receiving inspection of the offered product at the client with constant assessment of the supplier‘s ability. (On the basis of DIN 55350-11)

Supplier management

Management of the relationships with suppliers. This includes the selection of suppliers for products that are to be procured and the stipulations for monitoring and ongoing supplier evaluation.


Supplier rating

Periodic evaluation of the supplier by the customer on a regular basis and according to specific criteria, i.e., the evaluation after commencement of customer-supplier relationships.


Supplier relationship

Mutually beneficial supplier relationships are one of the eight quality management principles (see Quality management principles).


Supplier‘s declaration

See Self-declaration.


Supply chain management

Optimization of the flows of materials, good and information among several partners with the use of logistics service providers.


Supply Chain Quality

Optimization of all elements in a value chain.


Support process

Process that fulfils supporting tasks for the core processes. Support processes accompany the core processes and supply data and information or regulate administrative sequences. They do not have a directly value-added character and the customer is not willing to pay directly for support processes. However maintaining these processes can be just as important as maintaining core processes (see Key process). Example: A functioning computer system has a strategic significance for data administration in banks.


Surveillance audit

Audit that is primarily conducted annually by the certification company in order to monitor the organization‘s quality management system. Periodic surveillance audits are required in order for the certificate to remain valid throughout its term. These audits are usually not as extensive as the certification audit.



Strength – Weakness – Opportunity – Threats:
Tool for situation analysis and strategy formulation that examines strengths, weaknesses, opportunities and threats. A SWOT analysis first collects information in order to be able to assess a company or organization‘s strengths, weaknesses, opportunities and threats. The comparison of these points must take into account that weaknesses and strengths, as well as opportunities and threats, can be mutually dependent. Smaller companies may have greater flexibility than large companies, but at the same time they have less opportunity to raise outside capital. Consequently it is often not possible to eliminate weaknesses without simultaneously compromising existing strengths. Different strategies are: SO strategies (using a company‘s strengths for new opportunities, e.g., developing new products), ST strategies (using a company‘s strengths to reduce risks), WO strategies (opportunities are used by reducing weaknesses) and WT strategies (removing weaknesses in order to reduce risks).


Synectics meeting

Creativity technique and problem-solving method for complex tasks that stimulates thought processes that run without the person being conscious of them. It was developed by the American William Gordon (1961). In this method, apparently unrelated facts are brought together. The problem is first made unfamiliar through the formation of analogies and then confrontation with independent structures is used to find a link that leads to surprising solutions.


  1. Problem analysis and definition.
  2. Spontaneous solutions.
  3. Reformulation of the problem with regard to central points.
  4. Formation of natural analogies.
  5. Personal analogies (identification).
  6. Symbolic analogies (contradictions).
  7. Direct analogies (brainstorming),
  8. Analysis of the selected analogies.
  9. Application to the initial problem.
  10. Development of solutions.


A number of elements that are interrelated or interacting. (On the basis of ISO 9000:2015)


System approach to management

The system approach to management is one of the quality management principles (see Quality management principles).


System audit

Tool for the evaluation of the management system with regard to the fulfillment of the corporate policy and the comprehensive sets of rules. The system audit comprises the following phases: Preparation, document inspection, performance, audit report preparation, initiation of corrective actions. See Audit.


System FMEA

See Failure Mode and Effects Analysis.

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