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.

OCR. optical character recognition.

OEM. original equipment manufacturer.

OOP. object oriented programming.

object. In object oriented programming, A self contained module [encapsulation] of data and the programs [services] that manipulate [process] that data.

object code. (NIST) A code expressed in machine language ["1"s and "0"s] which is normally an output of a given translation process that is ready to be executed by a computer. Syn: machine code. Contrast with source code. See: object program.

object oriented design. (IEEE) A software development technique in which a system or component is expressed in terms of objects and connections between those objects.

object oriented language. (IEEE) A programming language that allows the user to express a program in terms of objects and messages between those objects. Examples include C++, Smalltalk and LOGO.

object oriented programming. A technology for writing programs that are made up of self-sufficient modules that contain all of the information needed to manipulate a given data structure. The modules are created in class hierarchies so that the code or methods of a class can be passed to other modules. New object modules can be easily created by inheriting the characteristics of existing classes. See: object, object oriented design.

object program. (IEEE) A computer program that is the output of an assembler or compiler.

octal. The base 8 number system. Digits are 0, 1, 2, 3, 4, 5, 6, & 7.

on-line. (IEEE) Pertaining to a system or mode of operation in which input data enter the computer directly from the point of origin or output data are transmitted directly to the point where they are used. For example, an airline reservation system. Contrast with batch. See: conversational, interactive, real time.

operating system. (ISO) Software that controls the execution of programs, and that provides services such as resource allocation, scheduling, input/output control, and data management. Usually, operating systems are predominantly software, but partial or complete hardware implementations are possible.

operation and maintenance phase. (IEEE) The period of time in the software life cycle during which a software product is employed in its operational environment, monitored for satisfactory performance, and modified as necessary to correct problems or to respond to changing requirements.

operation exception. (IEEE) An exception that occurs when a program encounters an invalid operation code.

operator. See: end user.

optical character recognition. An information processing technology that converts human readable data into another medium for computer input. An OCR peripheral device accepts a printed document as input, to identify the characters by their shape from the light that is reflected and creates an output disk file. For best results, the printed page must contain only characters of a type that are easily read by the OCR device and located on the page within certain margins. When choosing an OCR product, the prime consideration should be the program's level of accuracy as it applies to the type of document to be scanned. Accuracy levels less than 97% are generally considered to be poor.

optical fiber. Thin glass wire designed for light transmission, capable of transmitting billions of bits per second. Unlike electrical pulses, light pulses are not affected by random radiation in the environment.

optimization. (NIST) Modifying a program to improve performance; e.g., to make it run faster or to make it use fewer resources.

Oracle. A relational database programming system incorporating the SQL programming language. A registered trademark of the Oracle Corp.

original equipment manufacturer. A manufacturer of computer hardware.

overflow. (ISO) In a calculator, the state in which the calculator is unable to accept or process the number of digits in the entry or in the result. See: arithmetic overflow.

overflow exception. (IEEE) An exception that occurs when the result of an arithmetic operation exceeds the size of the storage location designated to receive it.

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.