Software Engineering Glossary

Software Engineering Glossary

"E" Glossary Content

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E-R diagram	Acronym for entity-relationship diagram.
early-failure period	The period of time in the life cycle of a system or component during which hardware failures occur at a decreasing rate as problems are detected and repaired. Syn: burn-in period. Contrast with: constant-failure period; wearout-failure period. See also: bathtub curve.
echo	To return a transmitted signal to its source, often with a delay to indicate that the signal is a reflection rather than the original. A returned signal, as in (1).
ECP	Acronym for engineering change proposal.
edit	To modify the form or format of computer code, data, or documentation; for example, to insert, rearrange, or delete characters.
editor	See: text editor. See: linkage editor.
effective address	The address that results from performing any required indexing, indirect addressing, or other address modification on a specified address. Note: If the specified address requires no modification, it is also the effective address. See also: generated address; indirect address; relative address.
effective instruction	The computer instruction that results from performing any required indexing, indirect addressing, or other modification on the addresses in a specified computer instruction. Note: If the specified instruction requires no modification, it is also the effective instruction. See also: absolute instruction; direct instruction; immediate instruction; indirect instruction.
effective process	A process that can be characterized as practiced, documented, enforced, trained, measured, and able to improve. See also: well-defined process.
efferent	Pertaining to a flow of data or control from a superordinate module to a subordinate module in a software system. Contrast with: afferent.
efficiency	The degree to which a system or component performs its designated functions with minimum consumption of resources. See also: execution efficiency; storage efficiency.
egoless programming	A software development technique based on the concept of team, rather than individual, responsibility for program development. Its purpose is to prevent individual programmers from identifying so closely with their work that objective evaluation is impaired.
embedded computer system	A computer system that is part of a larger system and performs some of the requirements of that system; for example, a computer system used in an aircraft or rapid transit system.
embedded object	Information in a document that is a copy of information created in another application. By choosing an embedded object, you can start the application that was used to create it while remaining in the document you're working in.
embedded software	Software that is part of a larger system and performs some of the requirements of that system; for example, software used in an aircraft or rapid transit system.
emulation	A model that accepts the same inputs and produces the same outputs as a given system. See also: simulation. The process of developing or using a model as in (1).
emulator	A device, computer program, or system that accepts the same inputs and produces the same outputs as a given system. See also: simulator.
encapsulated PostScript (EPS) file	A PostScript file with header information about the file. EPS files may print faster than other graphical representations. Some Windows-based and MS-DOS-based graphical applications can import EPS files. Refer to the documentation supplied with your application to determine whether this capability is supported.
encapsulation	A software development technique that consists of isolating a system function or a set of data and operations on those data within a module and providing precise specifications for the module. See also: data abstraction; information hiding.
end user	The individual or group who will use the system for its intended operational use when it is deployed in its environment.
end user representatives	A selected sample of end users who represent the total population of end users.
engineering	The application of a systematic, disciplined, quantifiable approach to structures, machines, products, systems, or processes.
engineering change	In configuration management, an alteration in the configuration of a configuration item or other designated item after formal establishment of its configuration identification. See also: configuration control; engineering change proposal. Contrast with: deviation; waiver.
engineering change proposal (ECP)	In configuration management, a proposed engineering change and the documentation by which the change is described and suggested. See also: configuration control.
engineering group	A collection of individuals (both managers and technical staff) representing an engineering discipline. Examples of engineering disciplines include systems engineering, hardware engineering, system test, software engineering, software configuration management, and software quality assurance.
entity	In computer programming, any item that can be named or denoted in a program. For example, a data item, program statement, or subprogram.
entity attribute	A named characteristic or property of a design entity. It provides a statement of fact about the entity.
entity-relationship (E-R) diagram	A diagram that depicts a set of real-world entities and the logical relationships among them. Syn: entity-relationship map. See also: data structure diagram.
entity-relationship (E-R) map	See: entity-relationship diagram.
entrance	See: entry point.
entry	See: entry point.
entry point	A point in a software module at which execution of the module can begin. Syn: entrance; entry. Contrast with: exit. See also: reentry point.
enumeration type	A discrete data type whose members can assume values that are explicitly defined by the programmer. For example, a data type called COLORS with possible values RED, BLUE, and YELLOW. Contrast with: character type; integer type; logical type; real type.
environment variable	A string consisting of environment information, such as a drive, path, or filename, associated with a symbolic name that can be used by MS-DOS and Windows. You use the set command at the command prompt or in the AUTOEXEC.BAT file to define environment variables.
epilog breakpoint	A breakpoint that is initiated upon exit from a given program or routine. Syn: prolog breakpoint. Contrast with: prolog breakpoint. See also: code breakpoint; data breakpoint; dynamic breakpoint; programmable breakpoint; static breakpoint.
equivalent faults	Two or more faults that result in the same failure mode.
error	(1) The difference between a computed, observed, or measured value or condition and the true, specified, or theoretically correct value or condition. For example, a difference of 30 meters between a computed result and the correct result 2. An incorrect step, process, or data definition. For example, an incorrect instruction in a computer program. An incorrect result. For example, a computed result of 12 when the correct result is 10. A human action that produces an incorrect result. For example, an incorrect action on the part of a programmer or operator. Note: While all four definitions are commonly used, one distinction assigns definition 1 to the word "error," definition 2 to the word "fault," definition 3 to the word "failure," and definition 4 to the word "mistake." See also: dynamic error; fatal error; indigenous error; semantic error; syntactic error; static error; transient error.
error model	In software evaluation, a model used to estimate or predict the number of remaining faults, required test time, and similar characteristics of a system. Syn: error prediction model.
error prediction	A quantitative statement about the expected number or nature of faults in a system or component. See also: error model. error seeding.
error prediction model	See: error model.
error seeding	The process of intentionally adding known faults to those already in a computer program for the purpose of monitoring the rate of detection and removal, and estimating the number of faults remaining in the program. Syn: bug seeding; fault seeding. See also: indigenous error.
error tolerance	The ability of a system or component to continue normal operation despite the presence of erroneous inputs. See also: fault tolerance; robustness.
evaluation	See: software capability evaluation.
event log	An event log provides a record of events such as logging on to or off of the network, or each time someone uses a resource on your computer.
event-driven review/activity	A review or activity that is performed based on the occurrence of an event within the project (e.g., a formal review or the completion of a life cycle stage). Contrast with: periodic review/activity
exception	An event that causes suspension of normal program execution. Types include addressing exception, data exception, operation exception, overflow exception, protection exception, underflow exception.
execute	To carry out an instruction, process, or computer program.
execution efficiency	The degree to which a system or component performs its designated functions with minimum consumption of time. See also: execution time; storage efficiency.
execution monitor.	See: monitor (1).
execution time	The amount of elapsed time or processor time used in executing a computer program. Note: Processor time is usually less than elapsed time because the processor may be idle (for example, awaiting needed computer resources) or employed on other tasks during the execution of a program. Syn: run time (3); running time. See also: overhead time.
execution trace	A record of the sequence of instructions executed during the execution of a computer program. Often takes the form of a list of code labels encountered as the program executes. Syn: code trace; control-flow trace. See also: retrospective trace; subroutine trace; symbolic trace; variable trace.
executive	See: supervisory program.
executive program	See: supervisory program.
executive state.	See: supervisor state.
exit	A point in a software module at which execution of the module can terminate. Contrast with: entry point. See also: return.
exit routine	A routine that receives control when a specified event, such as an error, occurs.
expand	To show more directory levels in the directory tree. With File Manager, you can expand a single directory level, one branch of the directory tree, or all branches at once.
expandability	See: extendability. explicit address. See: absolute address.
expanded memory	A type of memory, up to 8 MB, that is used by some MS-DOS-based applications. The use of expanded memory is defined by the Expanded Memory Specification (EMS). Expanded memory requires the use of an expanded-memory manager, such as EMM386.EXE.
extendability	The ease with which a system or component can be modified to increase its storage or functional capacity. Syn: expandability; extensibility. See also: flexibility; maintainability.
extended memory	Memory beyond 1 MB. To use extended memory with Windows , you need to have an extended-memory manager installed, such as HIMEM.SYS.
extended-level synthesizer	A synthesizer that can play a minimum of 16 notes on nine melodic instruments and 16 notes on eight percussive instruments simultaneously.
extensibility	See: extendability.
extension	The period and up to three characters at the end of a filename. An extension usually indicates the type of file or directory. For example, program files have default extensions of .COM or .EXE. Many applications use a default extension when you save a file the first time. For example, Windows Notepad adds .TXT to all filenames unless you specify otherwise.