Glossary - A

abstraction

a model of something that captures all of its essential characteristics while ignoring all of its diversionary details.
Contrast with class, object, and type.

acceptance test

a test of an application in its production environments to determine if it is acceptable to its customer organization.

acceptance testing

the final launch testing of an application in its production environments to determine if it is acceptable to its customer organization.

accessability

(a quality factor measuring the degree to which an application or user interface is actually usable by users with common disabilities.

accessability requirement

a user-oriented quality requirement specifying the degree to which an application or user interface shall be usable by users with common disabilities, whether auditory, visual, physical, or cognitive.

access control

a security mechanism for granting and restricting access to the functionality and data of an application or component, and therefore a mechanism for implementing an authorization security requirement.

accident

an unplanned and unintended (but not necessarily unexpected) event or series of related events resulting in harm to a valuable asset

accident probability level

a categorization of accidents based on an estimate of their probability of occurrence.
Examples include frequent, probable, unlikely, remote, and negligible.

accident severity

a categorization of accidents based on an assessment of the magnitude of their negative consequences.
Examples include catastrophic, critical, marginal, and negligible.

accuracy

a quantitative quality factor measuring the magnitude of a defect.
For example, a temperature sensor a temperature sensor is accurate to .1 degree Celsius if the temperature measurement returned by the temperature sensor is always within .1 degree of the true temperature.
Contrast with allowable latent defects, precision, and timeliness.

accuracy requirement

a user-oriented correctness quality requirement specifying the maximum permitted magnitude of defects (i.e., deviations of the average measurement from their true value).

activity

the highest-level work unit consisting of a cohesive collection of tasks that are performed by one or more collaborating producers when producing a set of related work products or providing one or more related services.
Contrast with work flow, task, and technique.
See also architecture engineeringing, configuration management. content management, deployment, design, digital branding, implementation, integration, maintenance, metrics engineering, operations, process engineering, program management, project management, quality engineering, requirements engineering reuse engineering, risk management, security engineering, testing, and training.

activity diagram

a diagram documenting the control flow between related use cases.

actor

any external that primarily represents one or more people:

• role,
• team, or
• organization.

Note that the term actor often refers to the role that is played by a person, whereas in English, the term actor means the person that plays the role. Thus, the word "actor" is a misnomer and a source of confusion. The word "external role" would be more accurate and less misleading.
Note that in UML, an actor refers to any external, and the stick figure icon for an actor can represent a hardware device or application. This is also misleading.

actor card

a large index card used during the requirements elicitation task to informally document a single actor.

actor guidelines

guidelines for identifying, analyzing, and specifying actors.

actor specification

a subsection of the system requirements specification that specifies a single actor in terms of its:

• Definition.
• Responsibilities.
• Required Capabilities.
• Associated Use Case Diagram.
• Associated Use Case Specifications.

actuator

a hardware output device that translates electrical signals into mechanical actions.
For example a stepper motor that turns its shaft a certain amount in response to an electrical signal received via a digital-to-analog converter from a computer.

air conditioner

a hardware component used in a data center to cool the server computers.

allowable latent defects

(1) a user-oriented c correctness quality requirement specifying the degree to which an application, component, or other work product shall be free from defects upon delivery to the customer organization.

(2) a quality factor measuring the degree to which an application, component, or other work product is actually free from defects upon delivery to the customer organization, measured in terms of either known (but not fixed) or estimated remaining defects.
Contrast with accuracy, precision, and timeliness.

alpha testing

the launch testing consisting of the development organization's initial internal dry runs of the application's acceptance tests in the production environments.

analog-to-digital converter (ADC)

a hardware input device that translates the input device’s (e.g., sensor) analog signals into the corresponding digital signals required by a computer.
Contrast digital-to-analog converter.

applet

a Java program that is downloadable to a client computer over the Internet.
Contrast with servlet.

application

a major, fully-functional, stand-alone integration work product that is developed by a development organization for use by one or more user organizations. An application can be a system containing both hardware and software or else pure software.

application business case

an architecture work product produced during business engineering that documents the results of a cost/benefit analysis of a single application.

application completion project

a project, the mission of which is to complete a new version of an application based on the results of an application estimation project.

application development project

a project, the mission of which is to develop a new version of an application.
Contrast with business reengineering project.

application domain

the subject matter of an application from the perspective of its user organizations.

application estimation project

a project, the mission of which is to estimate the time, cost, and effort required to develop a version of an application.

application operation

the operations subactivity of operating an application.

application requirements engineering

requirements engineering performed to produce the requirements of an application.

application retirement project

a project, the mission of which is to retire an application from service.

application selection

the architecture engineering task of a business [re]engineering endeavor during which potential new applications or new versions of existing applications are evaluated and selected for development.

application server

a server computer that:

• Executes applications when requested by other computers.
• Stores business logic and the business model classes of applications.
• Serves requests for dynamic HTTP webpages from web servers.

application software architecture engineeringing

the architecture engineering subactivity performed to produce an application's software architecture.

application strategy

the architecture work product produced during business engineering that documents the customer organization's strategy for producing future applications.

application system architecture engineering

the architecture engineering subactivity performed to produce an application's system architecture.

application usage project

a project the mission of which is to operate and maintain an application.

application vision statement (AVS)

the requirements work product produced during application development that documents the customer organization's vision of a single application.
Contrast with business vision statement.

architect

the role that is played when a person produces an architecture.
For example: business architect, database architect, hardware architect, information architect, security architect, software architect, and system architect.

architecture engineering

the activity consisting of the cohesive collection of all tasks that primarily involve the production of one or more architectures.

architectural mechanism

a mechanism used during architecture engineering to solve an architectural problem.

architectural mechanism production

the architecture engineering task of an application development endeavor during which architectural mechanisms are produced.

architectural patterns selection

the architecture engineering task of an application development endeavor during which the architectural patterns are chosen for the application architectures.

architectural view

documentation of a part of an architecture that should typically include the following contents:

• Overview,
  which names the type of view, states the scope of the view, and defines the view (e.g., a configuration view of the system that shows how the system is decomposed into collaborating subsystems).
• View Diagram,
  which is a diagram that documents the relationships between the relevant architectural elements and which includes a legend defining the notation used (i.e., the icons for all nodes and arcs) on the diagram.
• Element Catalog,
  which lists and describes the relevant architectural elements (i.e., the nodes and arcs between nodes on the view diagram) in terms of their externally-visible characteristics and behavior.
• View Context,
  which shows how the architectural elements shown in the view are related to elements external to the view.
• Variability Guide,
  which documents how the view of the architecture provides any necessary variability (e.g., when the architecture is used to support multiple systems within a product line).
• Analysis and Rationale,
  which documents the reasons why the part of the architecture described by the view were selected (e.g., which briefly lists the relevant architectural drivers and provides compelling evidence that the architecture fullfils them).
• Alternatives Considered and Rejected,
  which briefly describes alternative architectures that were considered and rejected including the reasons for their rejection.
• Assumptions,
  which briefly lists any assumptions on which the chosen architecture was based.

architecture

the most important, pervasive, top-level, strategic inventions, decisions, and their associated rationales that:

• Concern the overall structure, behavior and abstractions of a business, application, component, or framework.
• Are produced during the architecture engineering activity.
• Therefore provide a blueprint for the design.

Note:

• Fulfill Requirements. An architecture must fulfill (and must therefore be validated against) the architecturally significant requirements.
• Drive and Constrain Design. An architecture has pervasive global implications that drive and constrain the local, tactical (i.e., detailed) design.
• How? vs. What? The architecture and design both answer the question “How?”, whereas the requirements answer the question “What?”.
• Differences. The architecture and design differ in:
  • Degree because the architecture provides the big picture viewpoint, whereas the design provides the close up viewpoint.
  • Kind because architectural decisions have global (i.e., strategic) impacts, whereas design decisions only have local (i.e., tactical) impacts.

See also:

• business architecture
• system architecture:
  • database architecture
  • hardware architecture
  • information architecture
  • software architecture
  • user interface architecture
• framework architecture

architecture document

a document in the architecture set of work products that formally documents an architecture.
See also business architecture document, system architecture document, and software architecture document.

architecture documentation

the architecture engineering task during which the various architectures are documented.

architecture evaluation team

the team that evaluates the work products produced by the architecture team

architecture integrity assurance

the architecture engineering task during which the architecture team ensures that the design and implementation of an application do not violate the integrity of its architectures.

architecture prototyping

the architecture engineering task during which executable software prototypes of the software architecture (a.k.a., executable architectures) are produced.

architecture reuse

the architecture engineering task of reusing all or part of a preexisting reusable architecture.

architecture set

the set of all work products that are produced during the architecture engineering activity.
Contrast with architecture set, configuration management set, deployment set, design set, implementation set, management set, process set, requirements set, and test set.

architecture team

the team that performs the architecture engineering tasks to produce the architecture work products.

as built

describing the actual developed application.
Contrast with as documented.

as documented

describing the documented architecture and design of an application as it existed before it was built.
Synonym as planned.
Contrast with as built.

assertion

a Boolean (i.e., logical) expression specifying the state of an application, object, or use case that must exist at one or more specific points during execution.
Note that assertions can be used to specify the designer's intent.
Note that assertions also improve robustness when used to raise exceptions when violated.
See also invariant, postcondition, and precondition.

audio artist

the role that is played when a person creates or obtains new audio content for one or more applications.

audit

a quality control technique that consists of the independent examination of a baseline by a project-external team to determine if it is complete and ready for release to the customer organization.
Note that audits are used to assess compliance with the contract, requirements specifications, design documents, standards, etc.
See also inspection, review, and walkthrough.

auditability

(1) a user-oriented quality requirement specifying the degree to which an application shall keep sufficient records to support a financial audit (e.g., to determine whether financial transactions have occurred as claimed).

(2) a quality factor measuring the degree to which an application actually keeps sufficient records to support a financial audit.
Contrast with nonrepudiation.

audit report

a quality engineering work product that documents the results of an audit.

authentication

(1) a user-oriented security quality requirement specifying the extent to which an application or component shall verify the identify of its externals.

(2) a quality factor measuring the extent to which an application or component actually verifies the identify of its externals.

(3) a security mechanism used to verify identities and thereby implement authentication requirements.
Note that authentication depends on identification.
Note that authentication requirements are typically implemented using one or more of the following types of security mechanisms:

• What You Know - for example, passwords or pass phrase, address, mother's maiden name, and last four digits of the social security number.
• What You Have - for example, a digital certificate, a token, and PKI-enabled smart card.
• Who You Are - Either physiological traits (e.g., finger print, hand print, face recognition, iris recognition, and retina scan) or behavioral characteristics (e.g., voice pattern, signature style, and keystroke dynamics).

Contrast with authorization and identification.

authorization

(1) a user-oriented security quality requirement explicitly specifying:

• Which externals have been granted the privileges to access or use specific application or component capabilities or information by a properly appointed person or persons on behalf of an organization.
• That access is prohibited unless specifically authorized.

(2) a quality factor measuring whether externals can access specific application or component capabilities or information if and only if they have actually been properly granted the privileges to do so.

(3) a security mechanism used to implement authorization requirements (e.g., by providing access control configuration and enforcement).
Note that authorization depends on prior identification and authentication.
Contrast with access control, authentication, and identification.

availability testing

the testing subactivity during which an integrated application is tested against its operational availability requirements.