Safety (DOD) Freedom from those conditions that can cause death, injury, occupational illness, or damage to or loss of equipment or property, or damage to the environment.

Sample One or more observations drawn from a larger collection of observations or universe (population).

Sample standard deviation chart (s chart) Control chart in which the standard deviation of the subgroup is tracked to determine the variation within a process over time. Sample standard deviation charts are usually paired with average charts for complete analysis.

Scatter Diagram show the pattern of relationship between two variables that are thought to be related. For example is their a relationship between out side temperature and cases of the common cold? As temperatures drop, do colds increase. The closer the points hug a diagonal line the more closely there is a one to one relationship.

Scatterplot A tool that studies the possible relationship between two variables expressed on the x-axis and y-axis of a graph. The direction and density of the points plotted will indicate various relationships or a lack of any relationship between the variables.

Seven tools of quality Quality improvement tools that include the histogram, Pareto chart, check sheet, control chart, cause-and-effect diagram, flowchart, and scatter diagram.

SFMEA System Failure Mode and Effects Analysis.

Shewhart cycle Another name for the Plan-Do-Check-Act cycle. It is also sometimes called the Deming cycle.

Shewhart, Walter A. The father of statistical process control or statistical quality control. He pioneered statistical quality control and improvement methods when he worked for Western Electric and Bell Telephone in the early decades of the 20th century.

Sigma is a statistical unit of measure which reflects process capability. The sigma scale of measure is perfectly correlated to such characteristics as defects per unit, parts per million defective, and the probability of a failure/error.

Significant Characteristics Product and process characteristics designated by the customer, including governmental regulatory and safety, and/or selected by the supplier through knowledge of the product and process.

Simulation analysis. (IEEE) A software V&V task to simulate critical tasks of the software or system environment to analyze logical or performance characteristics that would not be practical to analyze manually.

Simulation.(1) (NBS) Use of an executable model to represent the behavior of an object. During testing the computational hardware, the external environment, and even code segments may be simulated. (2) (IEEE) A model that behaves or operates like a given system when provided a set of controlled inputs. Contrast with emulation.

Simulator. IEEE) A device, computer program, or system that behaves or operates like a given system when provided a set of controlled inputs. Contrast with emulator. A simulator provides inputs or responses that resemble anticipated process parameters. Its function is to present data to the system at known speeds and in a proper format.

Simultaneous Engineering A way of simultaneously designing products, and the processes for manufacturing those products, through the use of cross functional teams to assure manufacturability and to reduce cycle time.

Six Sigma Structured application of the tools and techniques of Total Quality Management on a Project Basis to achieve strategic business results

Six Sigma a failure rate of 3.4 parts per million or 99.99966% good

Six Sigma Application of the define, measure, analyse, improve and control steps.

Sizing.(IEEE) The process of estimating the amount of computer storage or the number of source lines required for a software system or component. Contrast with timing.

Skill Ability to perform a task or function.

Software characteristic. An inherent, possibly accidental, trait, quality, or property of software; e.g., functionality, performance, attributes, design constraints, number of states, lines or branches.

Software design description. (IEEE) A representation of software created to facilitate analysis, planning, implementation, and decision making. The software design description is used as a medium for communicating software design information, and may be thought of as a blueprint or model of the system. See: structured design, design description, specification.

Software development plan. (NIST) The project plan for the development of a software product. Contrast with software development process, software life cycle.
software development process. (IEEE) The process by which user needs are translated into a software product. the process involves translating user needs into software

Software documentation. (NIST) Technical data or information, including computer listings and printouts, in human readable form, that describe or specify the design or details, explain the capabilities, or provide operating instructions for using the software to obtain desired results from a software system. See: specification; specification, requirements: specification, design; software design description; test plan, test report, user's guide.

Software element. (IEEE) A deliverable or in-process document produced or acquired during software development or maintenance. Specific examples include but are not limited to: (1) Project planning documents; i.e., software development plans, and software verification and validation plans.(2) Software requirements and design specifications.(3) Test documentation.(4) Customer-deliverable documentation.(5) Program source code.(6) Representation of software solutions implemented in firmware(7) Reports; i.e., review, audit, project status.(8) Data; i.e., defect detection, test. Contrast with software item. See: configuration item.

Software engineering environment. (IEEE) The hardware, software, and firmware used to perform a software engineering effort. Typical elements include computer equipment. compilers, assemblers, operating systems, debuggers, simulators, emulators, test tools, documentation tools, and database management systems.

Software engineering. (IEEE) The application of a systematic, disciplined, quantifiable approach to the development, operation, and maintenance of software; i.e., the application of engineering to software. See: project plan, requirements analysis, architectural design, structured design, system safety, testing, configuration management.

Software hazard analysis. (CDE, CDRH) The identification of safety-critical software, the classification and estimation of potential hazards, and identification of program path analysis to identify hazardous combinations of internal and environmental program conditions. See: risk assessment, software safety change analysis, software safety code analysis, software safety design analysis, software safety requirements analysis, software safety test analysis, system safety.

Software item. (IEEE) Source code. object code, job control code, control data, or a collection of these items. Contrast with software element.

Software life cycle. (NIST) Period of time beginning when a software product is conceived and ending when the product is no longer available for use The software life cycle is typically broken into phases denoting activities such as requirements, design, programming, testing, installation, and operation and maintenance. Contrast with software development process. See: waterfall model.

Software reliability. (IEEE) (1) the probability that software will not cause the failure of a system for a specified time under specified conditions. The probability is a function of the inputs to and use of the system in the software The inputs to the system determine whether existing faults, if and are encountered. (2) The ability of a program to perform its required functions accurately and reproducibly under stated conditions for a specified period of time.

Software review. (IEEE) An evaluation of software elements to ascertain discrepancies from planned results and to recommend improvement. This evaluation follows a formal process. Syn: software audit. See: code audit, code inspection, code review, code walkthrough, design review, specification analysis, static analysis.

Software safety code analysis. (IEEE) Verification that the safety-critical portion of the design are correctly implemented in the code. See: logic analysis, data analysis, interface analysis, constraint analysis, programming style analysis, non-critical code analysis, timing and sizing analysis, software hazard analysis, system safety.

Software safety design analysis. (IEEE) Verification that the safety-critical portion of the software design correctly implements the safety-critical requirements and introduces no new hazards. See: logic analysis, data analysis, interface analysis, constraint analysis, functional analysis, software element analysis, timing and sizing analysis, reliability analysis. software hazard analysis, system safety.

Software safety requirements analysis. (IEEE) Analysis evaluating software and interface requirements to identify errors and deficiencies that could contribute to a hazard. See: criticality analysis, specification analysis, timing and sizing analysis, different software systems analyses, software hazard analysis, system safety.

Software safety test analysis. (IEEE) Analysis demonstrating that safety requirements have been correctly implemented and that the software functions safely within its specified environment. Tests may include; unit level tests, interface tests, software configuration item testing, system level testing, stress testing, and regression testing. See: software hazard analysis, system safety.

Software .(ANSI) Programs, procedures, rules, and any associated documentation pertaining to the operation of a system. Contrast with hardware See: application software, operating system, system software. utility software.

Source code.(1) (IEEE) Computer instructions and data definitions expressed in a form suitable for input to an assembler, compiler or other translator. (2) The human readable version of the list of instructions [program] that cause a computer to perform a task. Contrast with object code. See: source program, programming language.

SPC Statistical Process Control The application of statistical methods to analyze data, study and monitor process capability and performance. Use of control charts to monitor process performance.

SPC Statistical Process Control: The use of statistical techniques such as control charts to analyze a process , enabling appropriate actions to achieve a stable process...

Special causes (Assignable Cause) Causes of variation in a process that are not inherent in the process itself but originate from circumstances that are out of the ordinary. Special causes are indicated by points that fall outside the limits of a control chart.

Specification analysis. (IEEE) Evaluation of each safety-critical software requirement with respect to a list of qualities such as completeness, correctness, consistency, testability. robustness, integrity, reliability, usability, flexibility, maintainability, portability, interoperability, accuracy, audibility, performance. internal instrumentation, security and training.

Specification limit An engineering or design requirement that must be met in order to produce a satisfactory product.

Specification tree. (IEEE) A diagram that depicts all of the specifications for a given system and

Specification, product. (IEEE) A document which describes the as built version of the software

Specification, requirements. (NIST) A specification that documents the requirements of a system or system component. It typically includes functional requirements. performance requirements, interface requirements, design requirements [attributes and constraints], development [coding] standards, etc Contrast with requirement.
specification, test case. See: test case.

Specification, design. (NIST) A specification that documents how a system is to be built. It typically includes system or component structure, algorithms, control logic, data structures, data set [file] use information, input/output formats, interface descriptions, etc Contrast with design standards, requirement. See: software design description.

Specification, functional. (NIST) A specification that documents the functional requirements for a system or system component. It describes what the system or component is to do rather than how it is to be built. Often part of a requirements specification. Contrast with requirement.

Specification. (IEEE) A document that specifies, in a complete, precise, verifiable manner, the requirements, design, behavior, or other characteristics of a system or component, and often, the procedures for determining whether these provisions have been satisfied. Contrast with requirement. See: specification, formal; specification, requirements; specification, functional; specification, performance; specification, interface; specification, design; coding standards; design standards.

Specifications are engineering requirements for judging the acceptability of a part characteristic. For the production part approval process, every feature of the product as identified by engineering specifications must be measured. Actual measurement and test results are required. Specifications should not be confused with control limits which represent "the voice of the process".

Spider Diagram A visual reporting tool for the performance of a number of indicators. Also known as a "radar chart" this tool makes visible the gaps between the current and desired performance.

Spiral model. (IEEE) A model of the software development process in which the constituent activities, typically requirements analysis, preliminary and detailed design. coding, integration, and testing, are performed iteratively until the software is complete Syn: evolutionary model, Contrast with incremental development; rapid prototyping; waterfall model.

SQA Supplier Quality Assistance

SQC Statistical Quality Control: The application of statistical techniques to measure variation in materials, parts, components, and products. The process of maintaining acceptable levels of product quality by using statistical techniques.

Stable Process A process from which all special causes of variation have been eliminated and only common causes remain.

Standard Deviation A statistical index of variability which describes the spread.

Standard operating procedures. (SOP) Written procedures [prescribing and describing the steps to be taken in normal and defined conditions] which are necessary to assure control of production and processes.

Static analysis. (1) (NBS) Analysis of a program that is performed without executing the program. (2) (IEEE) The process of evaluating a system or component based on its form, structure, content, documentation. Contrast with dynamic analysis. See: code audit, code inspection, code review, code walk-through, design review, symbolic execution.
static analyzer. (ANSI/IEEE) A software tool that aides in the evaluation of a computer program without executing the program. Examples include checkers, compilers, cross-reference generators, standards enforcers, and flow-charters.

Statistical Control Is the condition of a process from which all special causes of variation have been eliminated and only common causes remain. Statistical control is evidenced on ,a control chart by the absence of points beyond the control limits and by the absence of any non random patterns or trends.

Statistical process control (SPC) Analysis and control of a process through the use of statistical techniques, particularly control charts.

Statistical quality control (SQC) Analysis and control of quality through the use of statistical techniques, focus is on the product not the process.

Stratification A process of grouping data according to a common characteristic.
Structural variation Variation caused by recurring system-wide changes such as seasonal changes or long-term trends.

Structured design. (IEEE) Any disciplined approach to software design that adheres to specified rules based on principles such as modularity, top-down design, and stepwise refinement of data, system structure, and processing steps. See: data structure centered design, input-processing-output, modular decomposition, object oriented design, rapid prototyping, stepwise refinement, structured programming. transaction analysis, transform analysis, graphical software specification/design documents, modular software, software engineering.

Structured programming. (IEEE) Any software development technique that includes structured design and results in the development of structured programs. See: structured design.

Stub. (NES) Special code segments that when invoked by a code segment under test will simulate the behavior of designed and specified modules not yet constructed.

SubgroupA logical grouping of objects or events which displays only random event to event variations, e.g., the objects or events are grouped to create homogenous groups free of assignable or special causes. By virtue of the minimum within group variability, any change in the central tendency or variance of the universe will be reflected in the "subgroup to subgroup' variability.

Submission Level Refers to the level of evidence required for production part submissions.

Subroutine trace. (IEEE) A record of all or selected subroutines or function calls performed during the execution of a computer program and. optionally, the values of parameters passed to and returned by each subroutine or function. Syn: call trace. See: execution trace, retrospective trace, symbolic trace, variable trace.

Subroutine. (IEEE) A routine that returns control to the program or subprogram that called it. Note: This term is defined differently in various programming languages. See: module.

Subsystem A major part of a system which itself has the characteristics of a system, usually consisting of several components.

Supplier Anyone whose output (materials, information, service, etc.) becomes an input to another person or group in a process of work. A supplier can be external or internal to the organization.

Suppliers The people who provide inputs to jobs, whether from inside or outside Your Company. In quality improvement, the customer and supplier relationship become an interactive relationship that calls for agreeing to and communicating specifications.

Surveillance Audit A post-registration quality audits to ensure the quality systems is still effectively implemented and continuous improvement is evident.

Symbolic execution. (IEEE) A static analysts technique in which program execution is simulated using symbols, such as variable names, rather than actual values for input data, and program outputs are expressed as logical or mathematical expressions involving these symbols.

Symbolic trace. (IEEE} A record of the source statements and branch outcomes that are encountered when a computer program is executed using symbolic, rather than actual values for input data. See: execution trace. retrospective trace, subroutine trace, variable trace.

SYMPTOM That which serves as evidence of something not seen.
syntax. The structural or grammatical rules that define how symbols in a language are to be combined to form words, phrases, expressions, and other allowable constructs.

SYSTEM That which is connected according to a scheme

System A combination of several components or pieces of equipment integrated to perform a specific function.

System administrator. The person that is charged with the overall administration, and operation of a computer system. The System Administrator is normally an employee or a member of the establishment. Syn: system manager.

System analysis. (ISO) A systematic investigation of a real or planned system to determine the functions of the system and how they relate to each other and to any other system. See: requirements phase.

System design review. (IEEE) A review conducted to evaluate the manner in which the requirements for a system have been allocated to configuration items, the system engineering process that produced the allocation, the engineering planning for the next phase of the effort, manufacturing considerations, and the planning for production engineering. See: design review.

System design. (ISO) A process of defining the hardware and software architecture, components, modules, interfaces, and data for a system to satisfy specified requirements. See: design phase, architectural design, functional design.

System documentation. (ISO) The collection of documents that describe the requirements, capabilities, limitations, design,
operation, and maintenance of an information processing system. See: specification, test documentation, user's guide.

System integration. (ISO) The progressive linking and testing of system components into a complete system. See: incremental integration.

System life cycle. The course of developmental changes through which a system passes from its conception to the termination of its use; a.g., the phases and activities associated with the analysis. acquisition, design, development, test, integration, operation, maintenance, and modification of a system. See: software life cycle.

System safety. (DOD) The application of engineering and management principles, criteria, and techniques to optimize all aspects of safety within the constraints of operational effectiveness, time, and cost throughout all phases of the system life cycle. See: risk assessment, software safety change analysis, software safety code analysis, software safety design analysis, software safety requirements analysis, software safety test analysis, software engineering.

System software. (ISO) Application-independent software that supports the running of application software (2) (IEEE) Software designed to facilitate the operation and maintenance of a computer system and its associated programs: eg., operating systems, assemblers, utilities. Contrast with application software See: support software

System. (1) (ANSI) People, machines, and methods organized to accomplish a set of specific functions. (2) (DOD) A composite, at any level of complexity, of personnel, procedures, materials, tools, equipment, facilities, and software The elements of this composite entity are used together in the intended operational or support environment to perform a given task or achieve a specific purpose, support. or mission requirement.

Systematic Diagram method searches for the most appropriate and effective means of accomplishing given objectives. ... Systematic diagrams can be divided into two types: The constituent component analysis diagram breaks down the main subject into its basic elements and depicts their relationships to the objectives and means of obtaining those objectives. The plan development diagram systematically shows the means and procedures necessary to successfully implement a given plan. It is typically represented graphically either a horizontal or vertical tree structure connecting the elements.