October 11, 2016

Systems Modeling Language

From SysML.org:

What is SysML? The Systems Modeling Language (SysML) is general purpose visual modeling language for systems engineering applications. SysML is defined as a dialect of the Unified Modeling Language (UML) standard, and supports the specification, analysis, design, verification and validation of a broad range of systems and systems-of-systems. These systems may include hardware, software, information, processes, personnel, and facilities.

Why do Systems Engineers need SysML? During the last decade SysML has evolved into enabling technology for Model-Based Systems Engineering (MBSE), a Systems Engineering paradigm that emphasizes the application of rigorous visual modeling principles and best practices to Systems Engineering activities throughout the System Development Life Cycle (SDLC). These Systems Engineering activities include, but are not limited to, requirements analysis and verification, functional analysis and allocations, performance analysis, trade studies, and system architecture specification.

Recommended SysML Books:

A Practical Guide to SysML, 3rd Edition
by Sanford Friedenthal; Rick Steiner; Alan Moore
Published by Morgan Kaufmann, 2014

SysML Distilled: A Brief Guide to the Systems Modeling Language
by Lenny Delligatti
Published by Addison-Wesley Professional, 2013

SysML Basics:

SysML comprises nine (9) diagrams:

  • Activity diagram (abbreviated ACT or act)
  • Block Definition diagram (abbreviated BDD or bdd)
  • Internal Block diagram (abbreviated IBD or ibd)
  • Package diagram (abbreviated PKG or pkg)
  • Parametric diagram (abbreviated PAR or par)
  • Requirement diagram (abbreviated REQ or req)
  • Sequence diagram (abbreviated SD or sd)
  • State Machine diagram (abbreviated STM or stm)
  • Use Case diagram (abbreviated UC or uc)

Seven of the nine diagrams have corresponding UML 2 counterparts. The other two, the Parametric diagram and theRequirement diagram, are only in SysML.

Note that the above diagrams are views of the model: they are not the model themselves. The model is created and editing using an MBSE modeling tool (software application) such as one of the following commercial products:

The following are non-commercial products that can be downloaded for free: