Author Topic: SysML and compartments  (Read 1489 times)


  • EA User
  • **
  • Posts: 435
  • Karma: +0/-0
  • We have met the enemy, and he is us.<Pogo, 1970>
    • View Profile
SysML and compartments
« on: June 12, 2010, 12:55:45 pm »
One shortcoming in the EA implementation of SysML is its lack of support for compartment-based representations of SysML features. For example, the SysML specification (e.g. Figure 9.7 in section 9.4.3) shows a "flow properties" compartment with flow properties represented as attributes with "in", "out", or "inout" prefixes. EA, on the other hand, only provides* the composite diagram + Flow Property "part" as a "built-in" method of realizing a flow specification. Likewise, Block properties (parts) can only be displayed by showing the composite diagram contents, not by means of compartments (as shown in Table 8.1 of the SysML 1.1 spec).

Ideally, both representations should be available for a given set of model elements. In other words, it should be possible to represent properties on a SysML internal block diagram in a "properties" or "parts" compartment on the parent block definition diagram, or as elements in a diagram frame on the parent block definition diagram, depending on the "display features" options for the block. As it is, the need to use "show composite diagram contents" in order to display a block's owned features is clumsy and gets in the way of a compact, neat representation of SysML system models.

* It's possible to "fake in" compartment-based SysML features by judicious choice of attribute stereotypes, but this isn't directly supported by the SysML stereotypes provided by EA and is in any case just that - "faking it in".
Fred Woolsey
Interfleet Technology Inc.

Always be ready to laugh at yourself; that way, you beat everyone else to the punch.


  • EA User
  • **
  • Posts: 597
  • Karma: +13/-0
  • UML/EA Principal Consultant / Trainer
    • View Profile
Re: SysML and compartments
« Reply #1 on: June 12, 2010, 11:50:44 pm »
This has my vote! I teach SysML courses and it is quite frustrating to have to teach "workarounds" to the SysML spec.

EA would be so much better for SysMl if these compartments supported. But please add this as an option for each Block (extension to Feature Visibility dialog?) as well as for the complete diagram.

Oddly, SysML 1.0 (the original Add-In) went some way to support compartments in its options. But these were global for all Blocks on all diagrams. Parts list were supported, allocations were there in the options, but always greyed out.

follow me on Twitter