Full Glossary

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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 project‚s 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 system‚s 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-relationship diagram (E-R diagram) 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 engineers  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 system‚s 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 system‚s 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 organization‚s 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 organization‚s 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 organization‚s 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 program‚s 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 object‚s 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 system‚s 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 organization‚s 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 organization‚s 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 organization‚s 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 organization‚s 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)

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