|
Abstract Class
|
A class that has no direct
instances, but whose descendants may have direct instances. (12) See also
Concrete class.
|
|
Abstract operation
|
Defines the form or protocol of
the operation, but not its implementation. (12)
|
|
Acceptance testing
|
The process whereby actual users
test a completed information system, the end result of which is the users
acceptance of the system. (20) See also System testing.
|
|
Access method
|
An operating system algorithm for
storing and locating data in secondary memory. (17) See also File
organization.
|
|
Action stubs
|
That part of a decision table that
lists the actions that result for a given set of conditions. (9)
|
|
Activation
|
The time period during which an
object performs an operation. (12)
|
|
Actor
|
An external entity that interacts
with the system (similar to an external entity in data flow diagramming).
(12) See also Use-case.
|
|
Adaptive maintenance
|
Changes made to a system to evolve
its functionality to changing business needs or technologies. (21)
|
|
Afferent module
|
A module of a structure chart
related to input to the system. (18) See also Efferent module.
|
|
Affinity clustering
|
The process of arranging planning matrix
information so that clusters of information with some predetermined level or
type of affinity are placed next to each other on a matrix report. (5)
|
|
Aggregation
|
A part-of relationship between a
component object and an aggregate object. (12) See also Composition.
|
|
Alias
|
An alternative name given to an
attribute. (16)
|
|
Alpha testing
|
User testing of a completed
information system using simulated data. (20) See also Beta testing,
System testing.
|
|
Analysis
|
The third phase of the SDLC in
which the current system is studied and alternative replacement systems are
proposed. (1)
|
|
Analysis tools
|
CASE tools that enable automatic
checking for incomplete, inconsistent, or incorrect specifications in
diagrams, forms, and reports. (4)
|
|
Anomalies
|
Errors or inconsistencies that may
result when a user attempts to update a table that contains redundant data.
There are three types of anomalies: insertion, deletion, and modification
anomalies. (16) See also Normalization.
|
|
Application independence
|
The separation of data and the
definition of data from the applications that use these data. (1)
|
|
Application program interface
(API)
|
Software which allows a specific
front-end program development platform to communicate with a particular
back-end database engine, even when the front-end and back-end were not built
to be compatible. (19)
|
|
Application server
|
A computing server where data
analysis functions primarily reside. (19)
|
|
Application software
|
Computer software designed to
support organizational functions or processes. (1)
|
|
Association
|
A relationship between object
classes. (12) See also Association role.
|
|
Association class
|
An association that has attributes
or operations of its own, or that participates in relationships with other
classes. (12)
|
|
Association role
|
The end of an association which
connects it to a class. (12) See also Multiplicity.
|
|
Associative entity
|
An entity type that associates the
instances of one or more entity types and contains attributes that are
peculiar to the relationship between those entity instances. Also called a
gerund. (10)
|
|
Asynchronous message
|
A message in which the sender does
not have to wait for the recipient to handle the message. (12) See also
Sequence diagram, Simple message, Synchronous message.
|
|
Attribute
|
A named property or characteristic
of an entity that is of interest to the organization. (10) See also
Multivalued attribute.
|
|
Audit trail
|
A list of changes to a data file
which allows business transactions to be traced. Both the updating and use of
data should be recorded in the audit trail, since the consequences of bad
data should be discovered and corrected. (17)
|
|
Authorization rules
|
Controls incorporated to restrict
access to systems and data and also to restrict the actions that people may
take once in the system. (15)
|
|
Backward recovery (rollback)
|
An approach to rebuilding a file
in which before images of changed records are restored to the file in reverse
order until some earlier state is achieved. (17) See also Forward
recovery (rollforward).
|
|
Balancing
|
The conservation of inputs and
outputs to a data flow diagram process when that process is decomposed to a
lower level. (8)
|
|
Baseline modules
|
Software modules that have been
tested, documented, and approved to be included in the most recently created
version of a system. (21)
|
|
Baseline Project Plan
|
A major outcome and deliverable
from the project initiation and planning phase which contains the best
estimate of a projectâs scope, benefits, costs, risks, and resource
requirements. (6)
|
|
Batch processing
|
Information that is collected or
generated at some predetermined time interval and can be accessed via hard
copy or on-line devices. (14)
|
|
Behavior
|
Represents how an object acts and
reacts. (12)
|
|
Beta testing
|
User testing of a completed
information system using real data in the real user environment. (20) See
also Alpha testing.
|
|
Binary relationship
|
A relationship between instances
of two entity types. This is the most common type of relationship encountered
in data modeling. (10)
|
|
Biometric device
|
An instrument that detects
personal characteristics such as fingerprints, voice prints, retina prints,
or signature dynamics. (15)
|
|
Blocking factor
|
The number of physical records per
page. (17)
|
|
Bottom-up planning
|
A generic information systems
planning methodology that identifies and defines IS development projects
based upon solving operational business problems or taking advantage of some
business opportunities. (5) See also Top-down planning, Corporate
strategic planning.
|
|
Boundary
|
The line that marks the inside and
outside of a system and which sets off the system from its environment. (2)
|
|
Build routines
|
Guidelines that list the
instructions to construct an executable system from the baseline source code.
(21)
|
|
Business case
|
The justification for an
information system, presented in terms of the tangible and intangible
economic benefits and costs, and the technical and organizational feasibility
of the proposed system. (6)
|
|
Business Process Reengineering
(BPR)
|
The search for, and implementation
of, radical change in business processes to achieve breakthrough improvements
in products and services. (7) See also Disruptive technologies, key
business processes.
|
|
Business rules
|
Specifications that preserve the
integrity of a conceptual or logical data model. (10)
|
|
Calculated field
|
A field which can be derived from
other database fields. Also called computed or derived field. (17)
|
|
Candidate key
|
An attribute (or combination of
attributes) that uniquely identifies each instance of an entity type. (10) See
also Identifier, Primary key.
|
|
Cardinality
|
The number of instances of entity
B that can (or must) be associated with each instance of entity A. (10)
|
|
CASE
|
See Computer-aided software engineering.
|
|
Central transform
|
The area of a transform-centered
information system where the most important derivation of new information
takes place. (18) See also Transform analysis.
|
|
Class
|
See also Object class.
|
|
Class diagram
|
Shows the static structure of an
object-oriented model: the object classes, their internal structure, and the
relationships in which they participate. (12)
|
|
Class-scope attribute
|
An attribute of a class that
specifies a value common to an entire class, rather than a specific value for
an instance. (12)
|
|
Client
|
The (front-end) portion of the
client/server database system that provides the user interface and data
manipulation functions. (19)
|
|
Client/server architecture
|
A LAN-based computing environment
in which a central database server or engine performs all database commands
sent to it from client workstations, and application programs on each client
concentrate on user interface functions. (19)
|
|
Closed-ended questions
|
Questions in interviews and on
questionnaires that ask those responding to choose from among a set of
prespecified responses. (7) See also Open-ended questions.
|
|
Closed system
|
A system that is cut off from its
environment and does not interact with it. (2) See also Open system.
|
|
Code generators
|
CASE tools that enable the
automatic generation of program and database definition code directly from
the design documents, diagrams, forms, and reports stored in the repository.
(4)
|
|
Cohesion
|
The extent to which a system or a
subsystem performs a single function. (2)
|
|
Command language interaction
|
A human-computer interaction
method where users enter explicit statements into a system to invoke
operations. (15)
|
|
Competitive strategy
|
The method by which an
organization attempts to achieve its mission and objectives. (5)
|
|
Component
|
An irreducible part or aggregation
of parts that make up a system, also called a subsystem. (2) See also
Inter-related components.
|
|
Component diagram
|
Shows the software components or
modules and their dependencies. (12) See also Package.
|
|
Composition
|
A part object that belongs to only
one whole object and lives and dies with the whole. (12) See also
Aggregation.
|
|
Computer-aided software
engineering (CASE)
|
Software tools that provide
automated support for some portion of the systems development process. (4) See
also Cross life cycle CASE, I-CASE, Lower CASE, Upper CASE.
|
|
Computing infrastructure
|
All the resources and practices
required to help people adequately use computer systems to do their primary
work. (20) See also Support.
|
|
Conceptual data model
|
A detailed model that captures the
overall structure of organizational data while being independent of any
database management system or other implementation considerations. (10) See
also Entity-relationship data model, Logical data model.
|
|
Concrete class
|
A class that can have direct
instances. (12) See also Abstract class.
|
|
Concurrency control
|
A method for preventing loss of
data integrity due to interference between users in a multiuser environment.
(19)
|
|
Condition stubs
|
That part of a decision table that
lists the conditions relevant to the decision. (9)
|
|
Configuration management
|
The process of assuring that only
authorized changes are made to a system. (21)
|
|
Constraint
|
A limit to what a system can
accomplish. (2)
|
|
Constructor operation
|
An operation that creates a new
instance of a class. (12) See also Abstract operation, Query
operation, Update operation.
|
|
Context diagram
|
An overview of an organizational
system that shows the system boundary, external entities that interact with
the system, and the major information flows between the entities and the
system. (8) See also Data flow diagram.
|
|
Conversion
|
See Installation.
|
|
Corporate strategic planning
|
An ongoing process that defines
the mission, objectives, and strategies of an organization. (5)
|
|
Corrective maintenance
|
Changes made to a system to repair
flaws in its design, coding, or implementation. (21)
|
|
Coupling
|
The extent to which subsystems
depend on each other. (2)
|
|
Critical path scheduling
|
A scheduling technique where the
order and duration of a sequence of activities directly affect the completion
date of a project. (3)
|
|
Cross life cycle CASE
|
CASE tools designed to support
activities that occur across multiple phases of the systems development life
cycle. (4) See also Lower CASE, Upper CASE.
|
|
Cross referencing
|
A feature performed by a data
dictionary that enables one description of a data item to be stored and
accessed by all individuals so that a single definition for a data item is
established and used. (5)
|
|
Data
|
Raw facts about people, objects,
and events in an organization. (1)
|
|
Data compression technique
|
Pattern matching and other methods
which replace repeating strings of characters with codes of shorter length.
(17)
|
|
Data couple
|
A diagrammatic representation of
the data exchanged between two modules in a structure chart. (18) See also
Flag.
|
|
Data dictionary
|
The repository of all data
definitions for all organizational applications. (4)
|
|
Data flow
|
Data in motion, moving from one
place in a system to another. (1)
|
|
Data flow diagram
|
A picture of the movement of data
between external entities and the processes and data stores within a system.
(8)
|
|
Data-oriented approach
|
An overall strategy of information
systems development that focuses on the ideal organization of data rather
than where and how data are used. (1) See also Process-oriented
approach.
|
|
Data store
|
Data at rest, which may take the
form of many different physical representations. (8)
|
|
Data type
|
A detailed coding scheme
recognized by system software for representing organizational data. (17)
|
|
Database
|
A shared collection of logically
related data designed to meet the information needs of multiple users in an
organization. (1)
|
|
Database engine
|
The (back-end) portion of the
client/server database system running on the server and providing database
processing and shared access functions. (19)
|
|
Database management system (DBMS)
|
Software that is used to create,
maintain, and provide controlled access to user databases. (17)
|
|
Decision support systems (DSS)
|
Computer-based systems designed to
help organization members make decisions; usually composed of a database,
model base, and dialogue system. (Website) See also DSS Generators.
|
|
Decision table
|
A matrix representation of the
logic of a decision, which specifies the possible conditions for the decision
and the resulting actions. (19) See also Action stubs, Condition
stubs, Rules.
|
|
Decision tree
|
A graphical representation of a
decision situation in which decision points (nodes) are connected together by
arcs (one for each alternative on a decision) and terminate in ovals (the
action which is the result of all of the decisions made on the path that
leads to that oval). (9)
|
|
Decomposition
|
See Functional decomposition.
|
|
Default value
|
A value a field will assume unless
an explicit value is entered for that field. (17)
|
|
Degree
|
The number of entity types that
participate in a relationship. (10)
|
|
Design strategy
|
A high-level statement about the
approach to developing an information system. It includes statements on the
systemâs functionality, hardware and system software platform, and method for
acquisition. (11)
|
|
Desk checking
|
A testing technique in which the
program code is sequentially executed manually by the reviewer. (20)
|
|
DFD completeness
|
The extent to which all necessary
components of a data flow diagram have been included and fully described. (8)
|
|
DFD consistency
|
The extent to which information
contained on one level of a set of nested data flow diagrams is also included
on other levels. (8)
|
|
Diagramming tools
|
CASE tools that support the
creation of graphical representations of various system elements such as
process flow, data relationships, and program structures. (4)
|
|
Dialogue
|
The sequence of interaction
between a user and a system. (15)
|
|
Dialogue diagramming
|
A formal method for designing and
representing human-computer dialogues using box and line diagrams. (15)
|
|
Direct installation
|
Changing over from the old
information system to a new one by turning off the old system when the new
one is turned on. (20)
|
|
Discount rate
|
The rate of return used to compute
the present value of future cash flows. (6)
|
|
Disruptive technologies
|
Technologies that enable the
breaking of long-held business rules that inhibit organizations from making
radical business changes. (7) See also Business Process Reengineering
(BPR).
|
|
Distributed database
|
A single logical database that is
spread across computers in multiple locations which are connected by a data
communications link. (19) See also Location transparency.
|
|
Documentation
|
See External documentation, Internal documentation, System
documentation, User documentation.
|
|
Documentation generators
|
CASE tools that enable the easy
production of both technical and user documentation in standard formats. (4)
|
|
Domain
|
The set of all data types and
values that an attribute can assume. (10)
|
|
Drop-down menu
|
A menu positioning method that
places the access point of the menu near the top line of the display; when
accessed, menus open by dropping down onto the display. (15) See also
Pop-up menu.
|
|
DSS generators
|
General purpose computer-based
tools used to develop specific decision support systems. (Website)
|
|
Economic feasibility
|
A process of identifying the
financial benefits and costs associated with a development project. (6)
|
|
Efferent module
|
A module of a structure chart
related to output from the system. (18) See also Afferent module.
|
|
Electronic performance support
system (EPSS)
|
Component of a software package or
application in which training and educational information is embedded. An
EPSS can take several forms, including a tutorial, an expert system shell,
and hypertext jumps to reference material. (20)
|
|
Encapsulation
|
The technique of hiding the
internal implementation details of an object from its external view. (12)
|
|
Encryption
|
The coding (or scrambling) of data
so that they cannot be read by humans. (17)
|
|
End users
|
Non-information-system
professionals in an organization who specify the business requirements for
and use software applications. End users often request new or modified
applications, test and approve applications, and may serve on project teams
as business experts. (1)
|
|
End-user development
|
An approach to systems development
in which users who are not computer experts satisfy their own computing needs
through the use of high-level software and languages such as electronic
spreadsheets and relational database management systems. (1) See also
Help desk, Support.
|
|
Entity instance (instance)
|
A single occurrence of an entity
type. (10)
|
|
Entity-relationship data model
(E-R model)
|
A detailed, logical representation
of the entities, associations, and data elements for an organization or
business area. (10)
|
|
Entity-relationshipÊdiagramÊ(E-RÊdiagram)
|
A graphical representation of an
E-R model. (10)
|
|
Entity type
|
A collection of entities that
share common properties or characteristics. (10)
|
|
Environment
|
Everything external to a system
which interacts with the system. (2)
|
|
Event
|
Something that takes place at a
certain point in time; a noteworthy occurrence that triggers a state
transition. (12)
|
|
Exclusive relationships
|
A set of relationships for which
an entity instance can participate in only one of the relationships at a
time. (Website)
|
|
Executive information systems
|
See Executive support systems.
|
|
Executive support systems
|
Computer-based systems developed
to support the information-intensive but limited-time decision making of
executives (also referred to as executive information systems). (Website)
|
|
Expert systems
|
Computer-based systems designed to
mimic the performance of human experts. (Website)
|
|
External documentation
|
System documentation that includes
the outcome of structured diagramming techniques such as data flow and
entity-relationship diagrams. (20) See also Internal documentation.
|
|
External information
|
Information that is collected from
or created for individuals and groups external to an organization. (14) See
also Internal information.
|
|
Feasibility
|
See Economic feasibility, Legal and contractual feasibility,
Operational feasibility, Political feasibility, Schedule feasibility,
Technical feasibility.
|
|
Field
|
The smallest unit of named
application data recognized by system software. (17)
|
|
File organization
|
A technique for physically
arranging the records of a file on secondary storage devices. (17) See
also Access method, Hashed file organization, Indexed file organization,
Sequential file organization.
|
|
File server
|
A device that manages file
operations and is shared by each client PC attached to a LAN. (19) See
also Client/server architecture.
|
|
First normal form (1NF)
|
A relation that contains no
repeating data. (16) See also Normalization.
|
|
Flag
|
A diagrammatic representation of a
message passed between two modules. (18) See also Data couple.
|
|
Foreign key
|
An attribute that appears as a
nonkey attribute in one relation and as a primary key attribute (or part of a
primary key) in another relation. (16)
|
|
Form
|
A business document that contains
some pre-defined data and may include some areas where additional data are to
be filled in. An instance of a form is typically based on one database
record. (14)
|
|
Form and report generators
|
CASE tools that support the
creation of system forms and reports in order to prototype how systems will
"look and feel" to users. (4)
|
|
Form interaction
|
A highly intuitive human-computer
interaction method whereby data fields are formatted in a manner similar to
paper-based forms. (15)
|
|
Formal system
|
The official way a system works as
described in organizational documentation. (7) See also Informal
system.
|
|
Forward recovery (rollforward)
|
An approach to rebuilding a file
in which one starts with an earlier version of the file and either reruns
prior transactions or replaces a record with its image after each
transaction. (17) See also Backward recovery (rollback).
|
|
Functional decomposition
|
An iterative process of breaking
the description of a system down into finer and finer detail which creates a
set of charts in which one process on a given chart is explained in greater
detail on another chart. (8)
|
|
Functional dependency
|
A particular relationship between
two attributes. For any relation R, attribute B is functionally dependent on
attribute A if, for every valid instance of A, that value of A uniquely
determines the value of B. The functional dependence of B on A is represented
as A > B. (16) See also Partial functional dependency, Transitive
dependency.
|
|
Gantt chart
|
A graphical representation of a
project that shows each task activity as a horizontal bar whose length is
proportional to its time for completion. (3)
|
|
Generalization
|
See Website.
|
|
Hashed file organization
|
The address for each record is
determined using a hashing algorithm. (17)
|
|
Hashing algorithm
|
A routine that converts a primary
key value into a relative record number (or relative file address). (17)
|
|
Help desk
|
A single point of contact for all
user inquiries and problems about a particular information system or for all
users in a particular department. (20) See also Computing
infrastructure, Information center, Support.
|
|
Homonym
|
A single name that is used for two
or more different attributes (for example, the term invoice to refer to both
a customer invoice and a supplier invoice). (16)
|
|
Horizontal partitioning
|
Distributing the rows of a table
into several separate tables. (19) See also Vertical partitioning.
|
|
I-CASE
|
An automated systems development
environment that provides numerous tools to create diagrams, forms, and
reports; provides analysis, reporting, and code generation facilities; and
seamlessly shares and integrates data across and between tools. (4)
|
|
Icon
|
Graphical pictures that represent
specific functions within a system. (15) See also Object-based
interaction.
|
|
Identifier
|
A candidate key that has been
selected as the unique, identifying characteristic for an entity type. (10) See
also Candidate key, Primary key.
|
|
Implementation
|
The sixth phase of the SDLC in
which the information system is coded, tested, installed, and supported in
the organization. (1)
|
|
Incremental commitment
|
A strategy in systems analysis and
design in which the project is reviewed after each phase and continuation of
the project is rejustified in each of these reviews. (5)
|
|
Index
|
A table or other data structure
used to determine the location of rows in a file that satisfy some condition.
(17)
|
|
Indexed file organization
|
The records are either stored
sequentially or nonsequentially and an index is created that allows software
to locate individual records. (17)
|
|
Indifferent condition
|
In a decision table, a condition
whose value does not affect which actions are taken for two or more rules.
(9)
|
|
Informal system
|
The way a system actually works.
(7) See also Formal system.
|
|
Information
|
Data that have been processed and
presented in a form suitable for human interpreta-tion, often with the
purpose of revealing trends or patterns. (1)
|
|
Information center
|
An organizational unit whose
mission is to support users in exploiting information technology. (20) See
also Computing infrastructure, Help desk, Support.
|
|
Information repository
|
Automated tools to manage and
control access to organizational business information and application
portfolios as components within a comprehensive repository. (4)
|
|
Information systems analysis and
design
|
The complex organizational process
whereby computer-based information systems are developed and maintained. (1)
|
|
Information systems planning (ISP)
|
An orderly means of assessing the
information needs of an organization and defining the systems, databases, and
technologies that will best satisfy those needs. (5) See also
Corporate strategic planning, Top-down planning.
|
|
Inheritance
|
The property that occurs when
entity types or object classes are arranged in a hierarchy and each entity
type or object class assumes the attributes and methods of its ancestors;
that is, those higher up in the hierarchy. Inheritance allows new but related
classes to be derived from existing classes. (1) See also
Generalization.
|
|
Input
|
Whatever a system takes from its
environment in order to fulfill its purpose. (2)
|
|
Inspections
|
A testing technique in which
participants examine program code for predictable language-specific errors.
(20)
|
|
Installation
|
The organizational process of
changing over from the current information system to a new one. (20) See
also Direct installation, Parallel installation, Phased installation,
Single location installation.
|
|
Intangible benefit
|
A benefit derived from the
creation of an information system that cannot be easily measured in dollars
or with certainty. (6) See also Tangible benefit.
|
|
Intangible cost
|
A cost associated with an
information system that cannot be easily measured in terms of dollars or with
certainty. (6) See also Tangible cost.
|
|
Integrated CASE
|
See I-CASE.
|
|
Integration testing
|
The process of bringing together
all of the modules that a program comprises for testing purposes. Modules are
typically integrated in a top-down, incremental fashion. (20)
|
|
Interface
|
In systems theory, the point of
contact where a system meets its environment or where subsystems meet each
other. (2) In human-computer interaction, a method by which users interact
with information systems. (15)
|
|
Internal documentation
|
System documentation that is part
of the program source code or is generated at compile time. (20) See also
External documentation.
|
|
Internal information
|
Information that is collected,
generated, or consumed within an organization. (14) See also External
information.
|
|
Interrelated components
|
Dependence of one subsystem on one
or more subsystems. (2)
|
|
JAD session leader
|
The trained individual who plans
and leads Joint Application Design sessions. (7)
|
|
Joint Application Design (JAD)
|
A structured process in which
users, managers, and analysts work together for several days in a series of
intensive meetings to specify or review system requirements. (1)
|
|
Key business processes
|
The structured, measured set of
activities designed to produce a specific output for a particular customer or
market. (7) See also Business Process Reengineering (BPR).
|
|
Knowledge engineersÊ
|
Computer professionals whose job
it is to elicit knowledge from domain experts in order to develop expert
systems. (Website)
|
|
Legal and contractual feasibility
|
The process of assessing potential
legal and contractual ramifications due to the construction of a system. (6)
|
|
Level-0 diagram
|
A data flow diagram that
represents a systemâs major processes, data flows, and data stores at a high
level of detail. (8)
|
|
Level-n diagram
|
A DFD that is the result of n
nested decompositions of a series of subprocesses from a process on a level-0
diagram. (8)
|
|
Local area network (LAN)
|
The cabling, hardware, and
software used to connect workstations, computers, and file servers located in
a confined geographical area (typically within one building or campus). (19)
|
|
Location transparency
|
A design goal for a distributed
database which says that a user (or user program) requesting data need not
know at which site those data are located. (19)
|
|
Logical database model
|
A description of data using a
notation that corresponds to an organization of data used by database
management systems. (16) See also Relational database model.
|
|
Logical design
|
The fourth phase of the SDLC in
which all functional features of the system chosen for development in
analysis are described independently of any computer platform. (1)
|
|
Logical system description
|
Description of a system that
focuses on the systemâs function and purpose without regard to how the system
will be physically implemented. (2)
|
|
Lower CASE
|
CASE tools designed to support the
implementation and maintenance phases of the systems development life cycle.
(4) See also Upper CASE.
|
|
Maintainability
|
The ease with which software can
be understood, corrected, adapted, and enhanced. (21)
|
|
Maintenance
|
The final phase of the SDLC in
which an information system is systematically repaired and improved; or
changes made to a system to fix or enhance its functionality. (1; 21) See
also Adaptive maintenance, Corrective maintenance, Perfective
maintenance, Preventive maintenance.
|
|
Management information systems
(MIS)
|
Computer-based systems designed to
provide standard reports for managers about transaction data. (Website)
|
|
Mean time between failures (MTBF)
|
A measurement of error occurrences
that can be tracked over time to indicate the quality of a system. (21)
|
|
Menu interaction
|
A human-computer interaction
method where a list of system options is provided and a specific command is
invoked by user selection of a menu option. (15) See also Drop-down
menu, Pop-up menu.
|
|
Method
|
The implementation of an
operation. (12)
|
|
Middleware
|
A combination of hardware,
software, and communication technologies that bring together data management,
presentation, and analysis into a three-tiered client/server environment.
(19)
|
|
Mission statement
|
A statement that makes it clear
what business a company is in. (5)
|
|
Modularity
|
Dividing a system up into chunks
or modules of a relatively uniform size. (2) See also Cohesion,
Coupling.
|
|
Module
|
A self-contained component of a
system, defined by function. (18)
|
|
Multiple classification
|
Shows that an object is an
instance of more than one class. (12)
|
|
Multiplicity
|
Indicates how many objects
participate in a given relationship. (12)
|
|
Multivalued attribute
|
An attribute that may take on more
than one value for each entity instance. (10)
|
|
Natural language interaction
|
A human-computer interaction
method where inputs to and outputs from a computer-based application are in a
conventional speaking language such as English. (15)
|
|
Normal form
|
A state of a relation that can be
determined by applying simple rules regarding dependencies to that relation.
(16) See also Functional dependency.
|
|
Normalization
|
The process of converting com-plex
data structures into simple, stable data structures. (16)
|
|
Null value
|
A special field value, distinct
from 0, blank, or any other value, that indicates that the value for the
field is missing or otherwise unknown. (17)
|
|
Object
|
An entity that has a well-defined
role in the application domain and has state, behavior, and identity. (12; 1)
See also Object class, Object diagram.
|
|
Object-based interaction
|
A human-computer interaction
method where symbols are used to represent commands or functions. (15) See
also Icon.
|
|
Object class (class)
|
A set of objects that share a
common structure and a common behavior. (12; 1) See also Abstract
class, Concrete class.
|
|
Object diagram
|
A graph of instances that are
compatible with a given class diagram. (12)
|
|
Object-oriented analysis and
design (OOAD)
|
Systems development methodologies
and techniques based on objects rather than data or processes. (1)
|
|
Objective statements
|
A series of statements that
express an organizationâs qualitative and quantitative goals for reaching a
desired future position. (5)
|
|
On-line processing
|
The collection and delivery of the
most recent available information, typically through an on-line workstation.
(14)
|
|
One-time cost
|
A cost associated with project
start-up and development, or system start-up. (6)
|
|
Open-ended questions
|
Questions in interviews and on
questionnaires that have no prespecified answers. (7) See also
Closed-ended questions.
|
|
Open system
|
A system that interacts freely
with its environment, taking input and returning output. (2) See also
Closed system.
|
|
Operation
|
A function or a service that is
provided by all the instances of a class. (12) See also Abstract
operation, Constructor operation, Method, Polymorphism, Query operation,
Update operation.
|
|
Operational feasibility
|
The process of assessing the
degree to which a proposed system solves business problems or takes advantage
of business opportunities. (6)
|
|
Output
|
Whatever a system returns to its
environment in order to fulfill its purpose. (2)
|
|
Outsourcing
|
The practice of turning over
responsibility of some to all of an organizationâs information systems
applications and operations to an outside firm. (11)
|
|
Overriding
|
The process of replacing a method
inherited from a superclass by a more specific implementation of that method
in a subclass. (12)
|
|
Package
|
A set of cohesive, tightly coupled
classes representing a subsystem. (12) See also Component diagram.
|
|
Page
|
The amount of data read or written
in one secondary memory (disk) input or output operation. For I/O with a
magnetic tape, the equivalent term is record block. (17) See also
Blocking factor.
|
|
Parallel installation
|
Running the old information system
and the new one at the same time until management decides the old system can
be turned off. (20)
|
|
Partial functional dependency
|
A dependency in which one or more
nonkey attributes are functionally dependent on part, but not all, of the
primary key. (16)
|
|
Participatory Design (PD)
|
A systems development approach
that originated in Northern Europe in which users and the improvement in
their work lives are the central focus. (1)
|
|
Perfective maintenance
|
Changes made to a system to add
new features or to improve performance. (21)
|
|
PERT chart
|
A diagram that depicts project
activities and their inter-relationships. PERT stands for Program Evaluation
Review Technique. (3)
|
|
Phased installation
|
Changing from the old information
system to the new one incrementally, starting with one or a few functional
components and then gradually extending the installation to cover the whole
new system. (20)
|
|
Physical design
|
The fifth phase of the SDLC in
which the logical specifications of the system from logical design are
transformed into technology-specific details from which all programming and
system construction can be accomplished. (1)
|
|
Physical file
|
A named set of contiguous records.
(17)
|
|
Physical record
|
A group of fields stored in
adjacent memory locations and retrieved together as a unit. (17)
|
|
Physical system description
|
Description of a system that
focuses on how the system will be materially constructed. (2)
|
|
Picture (or template)
|
A pattern of codes that restricts
the width and possible values for each position of a field. (17)
|
|
Pilot installation
|
See Single location installation.
|
|
Pointer
|
A field of data that can be used
to locate a related field or record of data. (17)
|
|
Political feasibility
|
The process of evaluating how key
stakeholders within the organization view the proposed system. (6)
|
|
Polymorphism
|
The same operation may apply to
two or more classes in different ways. (12)
|
|
Pop-up menu
|
A menu positioning method that
places a menu near the current cursor position. (15)
|
|
Present value
|
The current value of a future cash
flow. (6)
|
|
Preventive maintenance
|
Changes made to a system to avoid
possible future problems. (21)
|
|
Primary key
|
See Identifier.
|
|
Primitive DFD
|
The lowest level of decomposition
for a data flow diagram. (8)
|
|
Process
|
The work or actions performed on
data so that they are transformed, stored, or distributed. (8)
|
|
Process-oriented approach
|
An overall strategy to information
systems development that focuses on how and when data are moved through and
changed by an information system. (1) See also Data-oriented approach.
|
|
Processing logic
|
The steps by which data are
transformed or moved and a description of the events that trigger these
steps. (1)
|
|
Project
|
A planned undertaking of related
activities to reach an objective that has a beginning and an end. (3)
|
|
Project close-down
|
The final phase of the project
management process that focuses on bringing a project to an end. (3)
|
|
Project execution
|
The third phase of the project
management process in which the plans created in the prior phases (project
initiation and planning) are put into action. (3)
|
|
Project identification and
selection
|
The first phase of the SDLC in
which an organizationâs total information system needs are identified,
analyzed, prioritized, and arranged. (1)
|
|
Project initiation
|
The first phase of the project
management process in which activities are performed to assess the size,
scope, and complexity of the project and to establish procedures to support
later project activities. (3)
|
|
Project initiation and planning
|
The second phase of the SDLC in which
a potential information systems project is explained and an argument for
continuing or not continuing with the project is presented; a detailed plan
is also developed for conducting the remaining phases of the SDLC for the
proposed system. (1)
|
|
Project management
|
A controlled process of
initiating, planning, executing, and closing down a project. (3)
|
|
Project manager
|
An individual with a diverse set
of skills--management, leadership, technical, conflict management, and
customer relationship--who is responsible for initiating, planning,
executing, and closing down a project. (3)
|
|
Project planning
|
The second phase of the project
management process which focuses on defining clear, discrete activities and
the work needed to complete each activity within a single project. (3)
|
|
Project workbook
|
An on-line or hard copy repository
for all project correspondence, inputs, outputs, deliverables, procedures,
and standards that is used for performing project audits, orientation of new
team members, communication with management and customers, scoping future
projects, and performing post-project reviews. (3) See also
Repository.
|
|
Prototyping
|
An iterative process of systems
development in which requirements are converted to a working system which is
continually revised through close work between an analyst and users. (1) See
also Rapid Application Development (RAD).
|
|
Pseudocode
|
A method for representing the
instructions in a module with language very similar to computer programming
code. (18)
|
|
Purpose
|
The overall goal or function of a
system. (2)
|
|
Query operation
|
An operation that accesses the
state of an object but does not alter the state. (12) See also
Abstract operation, Constructor operation, Update operation.
|
|
Rapid Application Development
(RAD)
|
Systems development methodology
created to radically decrease the time needed to design and implement
information systems. RAD relies on extensive user involvement, Joint
Application Design sessions, prototyping, integrated CASE tools, and code
generators. (13)
|
|
Record partitioning
|
The process of splitting logical
records into separate physical segments based on affinity of use. (17) See
also Horizontal partitioning, Vertical partitioning.
|
|
Recurring cost
|
A cost resulting from the ongoing
evolution and use of a system. (6)
|
|
Recursive foreign key
|
A foreign key in a relation that
references the primary key values of that same relation. (16)
|
|
Reengineering
|
Automated tools that read program
source code as input, perform an analysis of the programâs data and logic,
and then automatically, or interactively with a systems analyst, alter an
existing system in an effort to improve its quality or performance. (4) See
also CASE.
|
|
Referential integrity
|
An integrity constraint specifying
that the value (or existence) of an attribute in one relation depends on the
value (or existence) of an attribute in the same or another relation. (16)
|
|
Relation
|
A named, two-dimensional table of
data. Each relation consists of a set of named columns and an arbitrary
number of unnamed rows. (16)
|
|
Relational database model
|
A data model that represents data
in the form of tables or relations. (16)
|
|
Relationship
|
An association between the
instances of one or more entity types that is of interest to the
organization. (10) See also Instance connection.
|
|
Repeating group
|
A set of two or more multivalued
attributes that are logically related. (10)
|
|
Report
|
A business document that contains
only pre-defined data; that is, it is a passive document used solely for
reading or viewing. A report typically contains data from many unrelated
records or transactions. (14)
|
|
Repository
|
A centralized database that
contains all diagrams, form and report definitions, data structure, data
definitions, process flows and logic, and definitions of other organizational
and system components; it provides a set of mechanisms and structures to achieve
seamless data-to-tool and data-to-data integration. (4) See also
I-CASE, Information repository, Project workbook.
|
|
Resource
|
Any person, group of people, piece
of equipment, or material used in accomplishing an activity. (3)
|
|
Reusability
|
The ability to design software
modules in a manner so that they can be used again and again in different
systems without significant modification. (4)
|
|
Reverse engineering
|
Automated tools that read program
source code as input and create graphical and textual representations of
program design-level information such as program control structures, data
structures, logical flow, and data flow. (4) See also CASE.
|
|
Rules
|
That part of a decision table that
specifies which actions are to be followed for a given set of conditions. (9)
|
|
Schedule feasibility
|
The process of assessing the
degree to which the potential timeframe and completion dates for all major
activities within a project meet organizational deadlines and constraints for
affecting change. (6)
|
|
Scribe
|
The person who makes detailed
notes of the happenings at a Joint Application Design session. (7)
|
|
Second normal form (2NF)
|
A relation is in second normal
form if it is in first normal form and every nonkey attribute is fully
functionally dependent on the primary key. Thus no nonkey attribute is
functionally dependent on part (but not all) of the primary key. (16) See
also Functional dependency, Partial functional dependency.
|
|
Secondary key
|
One or a combination of fields for
which more than one record may have the same combination of values. (17)
|
|
Sequence diagram
|
Depicts the interactions among
objects during a certain period of time. (12)
|
|
Sequential file organization
|
The records in the file are stored
in sequence according to a primary key value. (17)
|
|
Service
|
See Method.
|
|
Simple message
|
A message that transfers control
from the sender to the recipient without describing the details of the
communication. (12) See also Asynchronous message, Sequence diagram,
Synchronous message.
|
|
Single location installation
|
Trying out a new information
system at one site and using the experience to decide if and how the new
system should be deployed throughout the organization. (20)
|
|
Slack time
|
The amount of time that an
activity can be delayed without delaying the project. (3)
|
|
Smart card
|
A thin plastic card the size of a
credit card with an embedded microprocessor and memory. (15)
|
|
Source/sink
|
The origin and/or destination of
data, sometimes referred to as external entities. (8)
|
|
Staged installation
|
See Phased installation.
|
|
Stakeholder
|
A person who has an interest in an
existing or new information system. A stakeholder is someone who is involved
in the development of a system, in the use of a system, or someone who has
authority over the parts of the organization affected by the system. (1)
|
|
State
|
Encompasses an objectâs properties
(attributes and relationships) and the values those properties have. (12) See
also Behavior.
|
|
State diagram
|
A model of the states of an object
and the events that cause the object to change from one state to another.
(12)
|
|
State transition
|
Changes in the attributes of an
object or in the links an object has with other objects. (12).
|
|
Statement of Work (SOW)
|
Document prepared for the customer
during project initiation and planning that describes what the project will
deliver and outlines generally at a high level all work required to complete
the project. (6)
|
|
Structure chart
|
Hierarchical diagram that shows how
an information system is organized. (18)
|
|
Structured English
|
Modified form of the English
language used to specify the logic of information system processes. Although
there is no single standard, Structured English typically relies on action
verbs and noun phrases and contains no adjectives or adverbs. (9)
|
|
Stub testing
|
A technique used in testing
modules, especially where modules are written and tested in a top-down
fashion, where a few lines of code are used to substitute for subordinate
modules. (20)
|
|
Support
|
Providing ongoing educational and
problem solving assistance to information system users. For in-house
developed systems, support materials and jobs will have to be prepared or
designed as part of the implementation process. (20) See also
Computing infrastructure, Help desk, Information center.
|
|
Synchronous message
|
A type of message in which the
caller has to wait for the receiving object to finish executing the called
operation before it can resume execution itself. (12) See also
Asynchronous message, Sequence diagram, Simple message.
|
|
Synonyms
|
Two different names that are used
to refer to the same data item (for example, car and automobile). (16)
|
|
System
|
An inter-related set of
components, with an identifiable boundary, working together for some purpose.
(2) See also Closed system, Open system.
|
|
System documentation
|
Detailed information about a
systemâs design specifications, its internal workings, and its functionality.
(20)
|
|
System librarian
|
A person responsible for
controlling the checking-out and checking-in of baseline modules for a system
when a system is being developed or maintained. (21)
|
|
System testing
|
The bringing together of all the
programs that a system comprises for testing purposes. Programs are typically
integrated in a top-down, incremental fashion. (20) See also
Acceptance testing, Alpha testing, Beta testing, Integration testing, Stub
testing.
|
|
Systems analyst
|
The organizational role most
responsible for the analysis and design of information systems. (1)
|
|
Systems development life cycle
(SDLC)
|
The traditional methodology used
to develop, maintain, and replace information systems. (1)
|
|
Systems development methodology
|
A standard process followed in an
organization to conduct all the steps necessary to analyze, design,
implement, and maintain information systems. (1)
|
|
Tangible benefit
|
A benefit derived from the
creation of an information system that can be measured in dollars and with
certainty. (6) See also Intangible benefit.
|
|
Tangible cost
|
A cost associated with an
information system that can be measured in terms of dollars and with
certainty. (6) See also Intangible cost.
|
|
Technical feasibility
|
A process of assessing the
development organizationâs ability to construct a proposed system. (6)
|
|
Ternary relationship
|
A simultaneous relationship among
instances of three entity types. (10)
|
|
Third normal form (3NF)
|
A relation is in third normal form
if it is in second normal form and no transitive dependencies exist. (16)
|
|
Three-tiered client/server
|
Advanced client/server
architectures in which there are three logical and distinct
applications--data management, presentation, and analysis--which are combined
to create a single information system. (19)
|
|
Top-down planning
|
A generic information systems
planning methodology that attempts to gain a broad understanding of the
information system needs of the entire organization. (5) See also
Bottom-up planning.
|
|
Transaction analysis
|
The process of turning data flow
diagrams of a transaction-centered system into structure charts. (18) See
also Transform analysis.
|
|
Transaction-centered system
|
An information system that has as
its focus the dispatch of data to their appropriate locations for processing.
(18)
|
|
Transaction processing systems
(TPS)
|
Computer-based versions of manual
organization systems dedicated to handling the organizationâs transactions;
e.g., payroll. (Website)
|
|
Transactions
|
Individual, simple events in the
life of an organization that contain data about organizational activity.
(Website)
|
|
Transform analysis
|
The process of turning data flow
diagrams of a transform-centered system into structure charts. (18) See
also Transaction analysis.
|
|
Transform-centered system
|
An information system that has as
its focus the derivation of new information from existing data. (18) See
also Central transform.
|
|
Transitive dependency
|
A functional dependency between
two (or more) nonkey attributes in a relation. (16) See also Third
normal form.
|
|
Triggering operation (trigger)
|
An assertion or rule that governs
the validity of data manipulation operations such as insert, update, and
delete. (10)
|
|
Turnaround document
|
Information that is delivered to
an external customer as an output that can be returned to provide new
information as an input to an information system. (14)
|
|
Unary relationship (recursive
relationship)
|
A relationship between the
instances of one entity type. (10)
|
|
Unit testing
|
Method in which each module is
tested alone in an attempt to discover any errors in its code. (20)
|
|
Update operation
|
An operation that alters the state
of an object. (12) See also Abstract operation, Constructor operation,
Query operation.
|
|
Upper CASE
|
CASE tools designed to support
information planning and the project identification and selection, project
initiation and planning, analysis, and design phases of the systems
development life cycle. (4) See also Lower CASE.
|
|
Usability
|
An overall evaluation of how a
system performs in supporting a particular user for a particular task. (14)
|
|
Use case
|
A complete sequence of related
actions initiated by an actor, it represents a specific way of using the
system. (12)
|
|
Use-case diagram
|
A diagram that depicts the use
cases and actors for a system. (12)
|
|
User documentation
|
Written or other visual
information about an application system, how it works, and how to use it.
(20)
|
|
Value chain analysis
|
The process of analyzing an
organizationâs activities to determine where value is added to products
and/or services and the cost are incurred for doing so; usually also includes
a comparison with the activities, added value, and costs of other
organizations for the purpose of making improvements in the organizationâs
operations and performance. (5)
|
|
Vertical partitioning
|
Distributing the columns of a
table into several separate tables. (19) See also Horizontal
partitioning.
|
|
View
|
A subset of the database that is
presented to one or more users. (15)
|
|
Walkthrough
|
A peer group review of any product
created during the systems development process. Also called structured
walkthrough. (6)
|
|
Well-structured relation
|
A relation that contains a minimum
amount of redundancy and allows users to insert, modify, and delete the rows
in a table without errors or inconsistencies. (16) See also
Normalization.
|
|
Work breakdown structure
|
The process of dividing the
project into manageable tasks and logically ordering them to ensure a smooth
evolution between tasks. (3)
|
