SE DSIG

SysML Partners is continuing to work towards a V1.0 specification to submit for adoption by the OMG in early 2005.  In August, the Partners presented a major update of the specification from the initial submission presented in January 2004. The Partners presented the revised submission for the SysML specification V0.85 to the OMG on November 3 at the Washington DC meeting.  This version was a minor refinement from the previous version V0.8. The SysML draft specification  was posted to the OMG site, and the ADTF presentation will posted shortly. Both can also be found at the SysML Partners website at www.sysml.org. 

The SysML presentation to the ADTF provided a status update from the revised submission presented to the ADTF in Montreal in August, which went into a fair amount of detail regarding the specification. During this presentation,  SysML Partners emphasized that they are working changes in response to more recent vendor feedback on ways to make the spec more implementable including:

a) drive towards a stereotype solution versus metaclass extensions

b) improve UML 2 compatibility (e.g. reuse of UML 2 structured class and ports)

c) simplify and refine the spec

At the last SysML Partners meeting in Montreal, we learned that there were some significant issues relative to how the SysML implements stereotypes. Many of the issues resulted from a lack of clarity in the UML 2 specification.  Some of these issues have subsequently been addressed by the UML 2 FTF.  As part of the SysML revised submission presentation, Alan Moore presented clarifications and minor refinements to the stereotype specification in the UML 2 superstructure in order to effectively apply stereotypes in SysML. Alan has been working closely with Bran Selic and others to ensure close coordination with UML 2.

Because  there  are still  outstanding  technical issues from the vendor feedback, a motion was requested and passed to present a third revised submission of SysML to the ADTF at the OMG Burlingame meeting in February 2005, with the goal of intiating adoption in early 2005. 

The OMG meeting in DC was held in conjunction with the INCOSE Mid Atlantic Regional Conference (INCOSE MARC 2004). There were several SysML related activities including:

- Key note presentation by Richard Soley, who is the OMG CEO, on Leveraging MDA for Model Driven Systems Engineering. His presentation can be found at: http://www.omg.org/~soley/mdase.ppt

- SysML Presentation (a variant of what was presented in Toulouse)

- Panel on SysML and DoDAF including panel members Alan Moore, Bran Selic, Bruce Douglass, Fatma Dandeshi, Sandy Friedenthal . Fatma presented a proposed roadmap for aligning SysML and DoDAF, and discussed the intent to issue an RFI for SysML/DoDAF Standardization at the Burlingame meeting. 

- First SysML tool demonstrated (Artisan Real Time Studio).

These events were very positive in terms of highlighting the interest and direction of SysML, and highlighting the potential synergy between the OMG's Model Driven Architecture (MDA) initiative and Model Driven Systems Engineering.  

The SE DSIG is planning to meet at the OMG meeting in Burlingame to  review and issue an RFI regarding the SysML/DoDAF Standardization mentioned above. In addition, there will be a meeting at the INCOSE IW as part of MDSD to discuss open issues to be addressed as part of SysML V1.1 and the follow-on planning .

The  Systems Modeling Language (SysML) is an extension of UML 2 that will support the specification, analysis, design, verification and validation of complex systems that include software-intensive, information-intensive, and physical systems.  A summary of SysML extensions include the following:

a) extensions to activity diagrams to support enhanced functional flow block diagrams and continuous behavior modeling

b) minor refinements to the UML 2 composite structure diagram, which in SysML is called an assembly diagram, that provide a more general purpose capability for modeling structure including system hierarchy, interconnection and flows between components. 

c) a new requirement diagram to bridge the design models with requirements management tools by providing a model of requirements and their relationships, including a trace relationship between requirements, a satisfy relationship between a requirement and design/implementation elements, and a verify relationship between requirements and verification elements suchas test cases.

d) a new parametric diagram to bridge the specification and design models with analysis tools by providing a model of parameters and the constraints between them, such as F=ma.

e) a generic allocation relationship that can be further specialized to support multiple types of allocation, including behavior to structure and logical to physical elements. 

f) alignment between AP-233 and SysML. This is initially focusing on the alignment between the SysML requirement diagram and AP-233 requirements module, but the approach that is being demonstrated is intended to support alignment of the two standards as they evolve over time. 

For a more detailed overview of SysML, refer to the paper presented at the INCOSE Symposium 2004 in Toulouse entitled "Extending UML to Support a Systems Modelling Language" by S. Friedenthal and C. Kobryn or the June Insight article on SysML.

Sanford Friedenthal

OMG SE DSIG Chair / SysML Cochair

Lockheed Martin Corporation

sanford.friedenthal@lmco.com

(703) 293-5557