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Systems Modeling Language – Wikipedia

480px-Sysml_diagrams_collageThe Systems Modeling Language (SysML) is a
general-purpose modeling
language for systems engineering applications. It
supports the specification, analysis, design, verification and validation
of a broad range of systems and systems-of-systems.

SysML was originally developed by an open source
specification project, and includes an open source license for
distribution and use.[1]
SysML is defined as an extension of a subset of the Unified Modeling Language (UML)
using UML’s
profile mechanism


SysML offers systems engineers several noteworthy improvements
over UML, which tends to be software-centric. These
improvements include the following:[1]

  • SysML’s semantics are more flexible and expressive. SysML
    reduces UML’s software-centric restrictions and adds two new
    diagram types, requirement and parametric diagrams. The former
    can be used for requirements
    ; the latter can be used for performance analysis
    and quantitative analysis. Consequent to these
    enhancements, SysML is able to model a wide range of systems,
    which may include hardware, software, information, processes,
    personnel, and facilities.
  • SysML is a smaller language that is easier to learn and
    . Since SysML removes many of UML’s
    software-centric constructs, the overall language measures
    smaller both in diagram types and total constructs.
  • SysML allocation tables support common kinds of
    allocations. Whereas UML provides only limited support for
    tabular notations, SysML furnishes flexible allocation tables
    that support requirements allocation, functional allocation,
    and structural allocation. This capability facilitates
    automated verification and validation
    (V&V) and gap analysis.
  • SysML model management constructs support models, views,
    and viewpoints. These constructs extend UML’s capabilities and
    are architecturally aligned with IEEE-Std-1471-2000 (IEEE Recommended Practice
    for Architectural Description of Software Intensive Systems).

SysML reuses seven of UML 2’s fourteen diagrams, and adds two
diagrams (requirement and parametric diagrams) for a total of
nine diagram types. SysML also supports allocation tables, a
tabular format that can be dynamically derived from SysML
allocation relationships. A table which compares SysML and UML
2 diagrams is available in the SysML FAQ.[2]

The advantages of SysML over UML for systems engineering become
obvious if you consider a concrete example, like modeling an
automotive system. With SysML you can use Requirement diagrams
to efficiently capture functional, performance, and interface
requirements, whereas with UML you are subject to the
limitations of Use Case Diagram to define high-level
functional requirements. Likewise, with SysML you can use
Parametric diagrams to precisely define performance and
quantitative constraints like maximum acceleration,
minimum curb
, and total air conditioning capacity. UML provides
no straightforward mechanism to capture this sort of essential
performance and quantitative information.

Concerning the rest of the automotive system, enhanced activity
and state machine diagrams can be used to
specify the embedded software control logic and
information flows for the on-board automotive computers. Other
SysML structural and behavioral diagrams can be used to model
factories that build the automobiles, as well as the interfaces
between the organizations that work in the factories.



List of
SysML Tools






Systems Modeling Language – Wikipedia, the free encyclopedia.