[Sea-sa] Minutes from 10 May 2021 SEA-SA working meeting on RASDS revisions

Tue May 11 21:37:17 UTC 2021

Notes from 10 May 2021 WebEx, RASDS subset discussion

Attendees: Krosley, Huang, Radulescu, Slane, Shames

SEA-SAWG working meetings for RASDS update task
Draft Agenda Topics:

  *   Feedback from TC20/SC14 meetings
  *   Review newest Operations viewpoint proposal
  *   Review changes to Physical viewpoint, including any structural, electrical, thermal, propulsion, etc aspects.
  *   Review handling of SE / ISO 15288 aspects within the Enterprise viewpoint
Develop “final” set of PPT representations of the Viewpoints and associated attributes (stakeholders, concerns, objects, relationships)

ISO TC20/SC13 and SC14 topic:

We discussed briefly the situation with regard the relationships among CCSDS, ISO TC20/SC13 and TC20/SC14.  For those who are unaware, there is a somewhat unusual relationship (from the ISO point of view) between CCSDS and ISO TC20/SC13.    Where most of the ISO technical committees (TC) and subcommittees (SC) operate wholly within ISO procedures, and have working groups that are empaneled an develop standards in that context, CCSDS operates outside that and by its own rules.   The ISO TC20/SC13 operates largely as an “after the fact” document review and approval body, and this is the way that this relationship was formulated back in Sept 1990 (we finally found the memo).  The current ISO headquarters leadership did not understand this relationship, and that has impacted some of the liaison work that we all wished to engage in, including the RASDS extensions and the shared use of the SANA Terminology registry.  We seem to be moving past this contretemps, but it is not yet fully behind us.  Stay tuned.

Operational Viewpoint discussion

Costin had prepared some draft materials for the Operational Viewpoint.  The intent, as stated in the RASDS overview materials, has been to add this new viewpoint in a form that would be consistent with the rest of the framework, but that would cover operations concerns such as processes, procedures, activity planning and monitoring, etc.  As such it is expected to reference, by correspondence, requirements and persons from the Enterprise viewpoint, functional elements from the Functional Viewpoint, or deployed systems elements from what has been called the Connectivity or Deployment viewpoint.  Coming to an understanding of just how this would work for this new viewpoint has taken some discussion, which was anticipated.
I provided Costin with a terminology set as a starting point, one that included common architecture terms as well as terms drawn from RASDS and other sources.  This is in spreadsheet form (see attached, terms in yellow need to be added).  After thinking about how to approach this issue Costin elected to use these terms, the Protégé tool and some OWL plug-ins, to create an ontology of these terms.  The current version of that, as revised after the meeting, is attached.  Everyone in the meeting found this to be a very useful way to document and display the fundamental set of terms and their relationships, which forms the meta-model for this viewpoint.  Some adjustments were made during the meeting, and others are probably warranted, so please review and provide feedback.  There are also some new terms that need definitions, so that is work to go, as is how to represent the process flows that are needed.  SysML style activity diagrams seem like an obvious approach.

One other new approach that was discussed is to use this same methodology and set of tools to produce similar meta-models for all of the RASDS viewpoints.  We have an old Protégé version using frames from 2004, but it may be better to just start from scratch with OWL.  This might prove a really accessible and understandable set of charts that we could put into a modeling annex.  We have been discussing a SysML annex, and that is still an option too, so this is an open point for discussion.  A set of models in OWL can be imported into other modeling tools, including SysML, so there may be some tangible benefits from such an approach.  Ramon Krosley will be looking to see if this works for the Physical/Structural VP that he will be working on next.  Costin will put the Protégé OWL model, and the terminology spreadsheet, into a folder at:

https://cwe.ccsds.org/sea/docs/Forms/AllItems.aspx?RootFolder=%2Fsea%2Fdocs%2FSEA%2DSA%2FDraft%20Documents%2FRASDS%20Revisions%202020%2FRASDS%20Revisions%20Model%20materials&FolderCTID=0x012000F83FD93BEFF45E4FB5D1769B01CA762F&View=%7BA709F322%2D0E67%2D45C7%2D932D%2DCB78C55CE268%7D

We will need to think about how to manage these OWL models so that we can handle multiple people working on them, or on different sections, and how to integrate them.  If anyone has experience of this please speak up.

There was an interesting, and hopefully productive, discussion about the relationships among these terms and how that relates to the “SE V” and the typical system design process.  At the top level requirements relate to mission goals, and those then result in mission scenarios.  The scenarios result in plans that align with mission modes (EDL, cruise, emergency, etc).  This process usually gets iterated at different “levels” of the design process, where the decomposition of level n requirements leads to level n+1 requirements, and scenarios, plans, procedures and processes evolve and are elaborated.  The assertion has been made that the definitions of these terms, the relationships, and flow among these elements remain as described in this meta-model, but there is a sort of recursion in the application of this at each “level”.  This needs to be evaluated and reconciled with the normal ways in which the “SE V” is understood to operate.  This is not a part of the Operations viewpoint, but of the Enterprise viewpoint.

Terminology Discussion

We need to review the terminology set and expand it to include any other Operational viewpoint terms.  We also need to incorporate, and normalize, any TC20/SC14 terms that must be accommodated.  Ideally these will all be integrated so that they fit into a single, interconnected, ontology.  We must be able to permit alternative, but identical, terms as well, where these are needed.  An example of this that has already come up is “person” and “people”.

Action Items:

  1.  The next Working Meetings are 24-26 May 2021, you should have them on your calendar.
  2.  All: review the attached Operations ontology, provide feedback
  3.  Costin/Daniel/Fred: review the Operational VP to provide any needed fixes, clarifications, examples, representations
  4.  Ramon/Fred: review the Physical/Structural VP and Services VP and provide any needed fixes, clarifications, examples, representations
  5.  All: consider whether the Engineering VP is sufficiently “seminal” to this extended RASDS++ treatment, for SC14 and CCSDS, that we need to add it as a formal VP or if we can just introduce it as a concept and leave it for SC14 to elaborate?
The files for review, and any added / background materials, will be placed in the CWE at: https://cwe.ccsds.org/sea/docs/Forms/AllItems.aspx?RootFolder=%2Fsea%2Fdocs%2FSEA%2DSA%2FDraft%20Documents%2FRASDS%20Revisions%202020&View=%7BA709F322%2D0E67%2D45C7%2D932D%2DCB78C55CE268%7D&&InitialTabId=Ribbon%2EDocument&VisibilityContext=WSSTabPersistence<https://urldefense.us/v3/__https:/cwe.ccsds.org/sea/docs/Forms/AllItems.aspx?RootFolder=*2Fsea*2Fdocs*2FSEA*2DSA*2FDraft*20Documents*2FRASDS*20Revisions*202020&View=*7BA709F322*2D0E67*2D45C7*2D932D*2DCB78C55CE268*7D&&InitialTabId=Ribbon*2EDocument&VisibilityContext=WSSTabPersistence__;JSUlJSUlJSUlJSUlJSUlJQ!!PvBDto6Hs4WbVuu7!a_SVsvZretRTgcV2pBqQJMpqZkYZYtGWYdOUMBgkQ5pO_FlhO2a9lhjEoIfBQVRU3PIZawEf$>

We will use this folder as we work up the revisions to this document.

Peter

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