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<p>Dear CESG,</p>
<p><br>
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<p>As is usual with liaison agreements, as opposed to specific project statements, they are written in very general terms. The feedback seems to be confusing the two. This is a request to create a specific liaison arrangement, not a specific CCSDS (or ISO
SC14) project.</p>
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</p>
<p>That said, the specific intent of this liaison arrangement is to create a frameowkr within which one or more future projects could be created. The motivation for this is the the ISO TC20/SC14 has found value in the CCSDS Reference Architecture for Space
Data Systems (RASDS), CCSDS 311.0-M-1 for describing the data systems aspects of the standards that they develop. The five provided viewpoints: Enterprise, Functional, Connectivity, Communications, and Information are just as well suited for their standards
as they are for CCSDS. <br>
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<p>However, what they have identified a use for are additional viewpoints that are particularly relevant for them, namely Physical and Operational (procedural). These are viewpoints that we typically do not use, but that they focus upon. So their intent is
to work with us to develop these added viewpoints to extend the basic set in RASDS. The exact details of how to do this are TBD, those will be developed once the speifics of the project(s), as opposed to the cooperative framework, are agreed upon.</p>
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<p>I will point out that the RASDS provides a methodology for describing space data system architectures and not a specific architecture. As stated in the intro to that document:</p>
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<p><span style="font-size: 12.000000pt; font-family: 'TimesNewRomanPSMT'"><span style="color: rgb(0, 111, 201);"></span><span style="color: rgb(0, 111, 201);">The RASDS is intended to provide a standardized approach for description of data system architectures
and high-level designs, which individual CCSDS working groups may use within CCSDS. This approach is aligned with current practices in the fields of system and software architecture and is specifically adapted for the space domain. While it is intended for
use within CCSDS, it is also suitable for use by mission and project design teams to describe system architectures and designs within the space domain. It does not propose any specific formal modeling method or tool, but can be adapted to use methods like
UML or SysML </span></span></p>
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The RASDS document uses PPT diagrams as the representation method, but the important concepts have to do with the use of viewpoints, views, clear identification of the kinds of objects and relationships shown in these views, and their use in addressing stakeholder
concerns. The other important concept is that of correspondence, which provides a method for relating abstract objects documented in one with to their concrete realizations in other views. All of these concepts and methods may have alternate representations
in SysML. At the time we produced RASDS there was not yet broad support for this, but that seems to have shifted, even within CCSDS, and so one possible future project might be to produce a
<span>mapping </span>from PPT representation to a SysML one.
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<p>Whether any of this goes forward is a matter of WG discussion and availability of resources. As with all CCSDS WG the assignment of resources is a matter of creating draft projects and seeking support for them from the interested agencies. I suggest that
we continue to adhere to this process, of separating liaison agreements from specific project work and allow this agreement to go forward in the normal way, without convolving project considerations into the discussion.</p>
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<p>Best regards, Peter</p>
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<div class="PlainText">_______________________________________________________<br>
<br>
Peter Shames<br>
Manager - JPL Data Systems Standards Program<br>
InterPlanetary Network Directorate<br>
Jet Propulsion Laboratory, MS 301-230<br>
California Institute of Technology<br>
Pasadena, CA 91109 USA <br>
<br>
Telephone: +1 818 354-5740, Fax: +1 818 393-0028<br>
<br>
Internet: Peter.Shames@jpl.nasa.gov<br>
________________________________________________________<br>
"We shall not cease from exploration, and the end of all our exploring<br>
will be to arrive at where we started, and know the place for the first time"<br>
<br>
T.S. Eliot<br>
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<div id="divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" style="font-size:11pt" color="#000000"><b>From:</b> CESG-All <cesg-all-bounces@mailman.ccsds.org> on behalf of Oliver, Brian (HQ-CG000)[Arctic Slope Technical Services, Inc.] <brian.oliver@nasa.gov><br>
<b>Sent:</b> Wednesday, January 3, 2018 6:26:57 PM<br>
<b>To:</b> cesg-all@mailman.ccsds.org<br>
<b>Cc:</b> CCSDS<br>
<b>Subject:</b> [Cesg-all] Results of Recent CESG Poll</font>
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<div>CESG E-Poll Identifier: CESG-P-2017-10-001 Approval of SC14 and SC13/CCSDS Information Exchange for Reference Architecture Extensions<br class="">
<br class="">
Results of CESG poll beginning 26 October 2017 and ending 4 December 2017:<br class="">
<br class="">
Abstain: 0 (0%)<br class="">
Approve Unconditionally: 2 (40%) (Burleigh, Shames)<br class="">
Approve with Conditions: 3 (60%) (Calzolari, Barkley, Merri)<br class="">
Disapprove with Comment: 0 (0%)<br class="">
<br class="">
CONDITIONS/COMMENTS:<span style="font-family: Tahoma; font-size: 13.333333015441895px;" class=""></span>
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<div class="">Mario Merri (Approve with Conditions):</div>
<div class="">The text of the resolution is not very clear and requires explanations. In particular: <br class="">
1. It is stated that "TC20/SC14 and the CCSDS liaison have reviewed this proposal ... to be sent for approval": who specifically has done this? <br class="">
<br class="">
2. The text implies that the joint SC13/SC14 reference architecture shall be created, maintained and evolved. On CCSDS side, something is being done to cover the CCSDS side. Is the same being done on SC14 side? Timescale? <br class="">
<br class="">
3. How will the joint architecture be described? Using the current approach adopted by CCSDS that is based on power point/document? <br class="">
<br class="">
4. What is the approach to harmonise the SC14 and SC13 reference architectures? What resources are required and where do they come from? <br class="">
<br class="">
5. Similarly, once the harmonised architecture exits, what resources are required to maintain it and evolve it and who will pay for this? <br class="">
<br class="">
6. Is the joint reference architecture meant to be an overall roadmap for SC13 and SC14, thus indicating completed, in progress and future work? <br class="">
<br class="">
7. What will be the governance of the harmonised architecture?<br class="">
<br class="">
Gian Paolo Calzolari (Approve with Conditions):
<div class="">I concur with the conditions expressed by MOIMS AD. It would be good discussing the matter CESG wide in a meeting/webex.<br class="">
</div>
<div class=""><br class="">
</div>
<div class="">Eric Barkley (Approve with Conditions):<br class="">
A minor editorial condition: Suggest replacing "they" in the last sentence of the resolution to "TSO/SC14 and SC13/CCSDS" (assuming this is who is meant by "they'). <br class="">
<br class="">
Total Respondents: 5<br class="">
No response was received from the following Area(s):<br class="">
<br class="">
SOIS<br class="">
<br class="">
SECRETARIAT INTERPRETATION OF RESULTS: Approved with Conditions<br class="">
PROPOSED SECRETARIAT ACTION: Generate CMC poll after conditions have been addressed</div>
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