Alternative Forms

• Sys abbreviation

Definitions

Definition 1 Computer Science

A system is any set of related and discrete IT components (computer hardware, software, data, and data operations) with the capability to collect, store, transform, and/or transmit information, that is regarded as a coherent whole. ^①④

A system as a set may be extended to comprise non-IT components (entities, procedures, processes, and activities) that play a role in the system. ^①

A system is defined by the system boundaries, that is the delimitation of the discrete components that are inside in contrast with the discrete components that are outside the set. Defining system boundaries with accuracy may be difficult, especially in complex and dynamic environments of densely interconnected and sometimes overlapping components. Desirable characteristics of system boundaries comprise: ^③

• Coherence of ownership and managerial control,

• Coherence of functional requirements or goal,

• Coherence of non-functional requirements, including security,

• Coherence of operational constraints.

A system is protected from the external environment by boundary controls. The effectiveness of the boundary controls determines the extent to which the security of the system is dependent on the security of the systems it is interconnected with. ^③

The term system may designate a system design (e.g. a software blueprint), a system package (e.g. a software product), or a system instance (e.g. an installed software). The terms system design, system package, or system instance may be used when the context is not sufficiently clear.

Disambiguation

The following terms are near synonymous but may be used with nuances:

• An Application Program is a system that derives its coherence from its capability to fulfill some functional requirements.

• An Information Security Domain is a system that comprises authorities, entities, identities, and authorizations that constitute a community of interest.

• The term Information System used with a definite article (e.g.: as in the information system) is used to designate the overall system of an organization, i.e. the super system that encompasses all the IT systems owned or managed by that organization.

• The term Information System used with an indefinite article (e.g.: as in an information system) focuses on how information flows throughout the system makes it a consistent whole.

• IT System focuses on the IT components of the system, i.e. hardware, software, data, and data processing.

• The term System is the most generic form. It should be preferred when referring to both IT (hardware, software, data, data processing) and non-IT (information, procedures, human activities) components

Sample Sentences

Bob developed system X by progressively adding new features. He did not follow architectural best practices and had no overall vision of the system. As time passed by, system X became more and more complex and hard to maintain. One day, Eve had no choice but to take the decision to decommission system X. In effect, system X was too obsolete and became an operational risk for the organization.

Conceptual Diagram

Open

Related Terms

Quotes

Bibliography

① Butterfield et al., 2016

② ESD-TR-73-278, Vol. 1, 1973

③ NIST SP 800-26, 2001

④ OMB A-130, 1996

See Also