Glossary of Computer Software Development Terminology

The terms are defined, as much as possible, using available standards. The source of such definitions appears immediately following the term or phrase in parenthesis, e.g. (NIST).

The source documents are listed at the bottom of this page.

V&V. verification and validation.

VAX. virtual address extension.

VLSI. very large scale integration.

VMS. virtual memory system.

VV&T. validation, verification, and testing.

valid. (1) Sound. (2) Well grounded on principles of evidence. (3) Able to withstand criticism or objection.

validate. To prove to be valid.

validation. (1) (FDA) Establishing documented evidence which provides a high degree of assurance that a specific process will consistently produce a product meeting its predetermined specifications and quality attributes. Contrast with data validation.

validation, process. (FDA) Establishing documented evidence which provides a high degree of assurance that a specific process will consistently produce a product meeting its predetermined specifications and quality characteristics.

validation, prospective. (FDA) Validation conducted prior to the distribution of either a new product, or product made under a revised manufacturing process, where the revisions may affect the product's characteristics.

validation protocol. (FDA) A written plan stating how validation will be conducted, including test parameters, product characteristics, production equipment, and decision points on what constitutes acceptable test results. See: test plan.

validation, retrospective. (FDA) (1) Validation of a process for a product already in distribution based upon accumulated production, testing and control data. (2) Retrospective validation can also be useful to augment initial premarket prospective validation for new products or changed processes. Test data is useful only if the methods and results are adequately specific. Whenever test data are used to demonstrate conformance to specifications, it is important that the test methodology be qualified to assure that the test results are objective and accurate.

validation, software. (NBS) Determination of the correctness of the final program or software produced from a development project with respect to the user needs and requirements. Validation is usually accomplished by verifying each stage of the software development life cycle. See: verification, software.

validation, verification, and testing. (NIST) Used as an entity to define a procedure of review, analysis, and testing throughout the software life cycle to discover errors, determine functionality, and ensure the production of quality software.

valid input. (NBS) Test data that lie within the domain of the function represented by the program.

variable. A name, label, quantity, or data item whose value may be changed many times during processing. Contrast with constant.

variable trace. (IEEE) A record of the name and values of variables accessed or changed during the execution of a computer program. Syn: data-flow trace, data trace, value trace. See: execution trace, retrospective trace, subroutine trace, symbolic trace.

vendor. A person or an organization that provides software and/or hardware and/or firmware and/or documentation to the user for a fee or in exchange for services. Such a firm could be a medical device manufacturer.

verifiable. Can be proved or confirmed by examination or investigation. See: measurable.

verification, software. (NBS) In general the demonstration of consistency, completeness, and correctness of the software at each stage and between each stage of the development life cycle. See: validation, software.

verify. (ANSI) (1) To determine whether a transcription of data or other operation has been accomplished accurately. (2) To check the results of data entry; e.g., keypunching. (3) (Webster) To prove to be true by demonstration.

version. An initial release or a complete re-release of a software item or software element. See: release.

version number. A unique identifier used to identify software items and the related software documentation which are subject to configuration control.

very large scale integration. A classification of ICs [chips] based on their size as expressed by the number of circuits or logic gates they contain. A VLSI IC contains 100,000 to 1,000,000 transistors.

virtual address extension. Identifies Digital Equipment Corporation's VAX family of computers, ranging from a desktop workstation to a large scale cluster of multiprocessors supporting thousands of simultaneous users.

virtual memory system. Digital Equipment Corporation's multiprocessing, interactive operating system for the VAX computers.

virus. A program which secretly alters other programs to include a copy of itself, and executes when the host program is executed. The execution of a virus program compromises a computer system by performing unwanted or unintended functions which may be destructive. See: bomb, trojan horse, worm.

volume. (ANSI) A portion of data, together with its data carrier, that can be handled conveniently as a unit; e.g., a reel of magnetic tape, a disk pack, a floppy disk.

Source Documents

1. The New IEEE Standard Dictionary of Electrical and Electronics Terms, IEEE Std. 100-1992.
2. IEEE Standards Collection, Software Engineering, 1994 Edition, published by the Institute of Electrical and Electronic Engineers Inc.
3. National Bureau of Standards [NBS] Special Publication 500-75 Validation, Verification, and Testing of Computer Software, 1981.
4. Federal Information Processing Standards [FIPS] Publication 101, Guideline For Lifecycle Validation, Verification, and Testing of Computer Software, 1983.
5. Federal Information Processing Standards [FIPS] Publication 105, Guideline for Software Documentation Management, 1984.
6. American National Standard for Information Systems, Dictionary for Information Systems, American National Standards Institute, 1991.
7. FDA Technical Report, Software Development Activities, July 1987.
8. FDA Guide to Inspection of Computerized Systems in Drug Processing, 1983.
9. FDA Guideline on General Principles of Process Validation, May 1987.
10. Reviewer Guidance for Computer Controlled Medical Devices Undergoing 510(k) Review, Office of Device Evaluation, CDRH, FDA, August 1991.
11. HHS Publication FDA 90-4236, Preproduction Quality Assurance Planning.
12. MIL-STD-882C, Military Standard System Safety Program Requirements, 19JAN1993.
13. International Electrotechnical Commission, International Standard 1025, Fault Tree Analysis.
14. International Electrotechnical Commission, International Standard 812, Analysis Techniques for System Reliability - Procedure for Failure Mode and Effects Analysis [FMEA].
15. FDA recommendations, Application of the Medical Device GMP to Computerized Devices and Manufacturing Processes, May 1992.
16. Pressman, R., Software Engineering, A Practitioner's Approach, Third Edition, McGraw-Hill, Inc., 1992.
17. Myers, G., The Art of Software Testing, Wiley Interscience, 1979.
18. Beizer, B., Software Testing Techniques, Second Edition, Van Nostrand Reinhold, 1990.
19. Additional general references used in developing some definitions are:
20. Bohl, M., Information Processing, Fourth Edition, Science Research Associates, Inc., 1984.
21. Freedman, A., The Computer Glossary, Sixth Edition, American Management Association, 1993.
22. McGraw-Hill Electronics Dictionary, Fifth Edition, 1994, McGraw-Hill Inc.
23. McGraw-Hill Dictionary of Scientific & Technical Terms, Fifth Edition, 1994, McGraw-Hill Inc..
24. Webster's New Universal Unabridged Dictionary, Deluxe Second Edition, 1979.

The bulk of this information was obtained from FDA.gov.