[Css-rasg] Viewpoints and views (further follow up on AI #017)

[Barkley, Erik J (317H)]

Roger,

Thank you very much for the inputs. I have finally had a chance to read through the inputs.  Some comments follow.

I think that we need to consider a bit of formalism with regard to views and viewpoints.  I think really what you have proposed are viewpoints. Let me elaborate a bit by saying that I think we could state that viewpoints are really specifications from which views are then constructed. Taking a look at the draft concept paper, on page 13, there is, in a tabular fashion, an attempt to state what the specification viewpoints are for the various views:


Viewpoint Element

Viewpoint


Enterprise


Functional


Services


Communications


Information

Main concepts

CCSDS Processes & procedures; Policies; Principles;
Org structure (role, responsibility, function); Charters;
Members;
Requirements;
Mission models;


Use cases;
Scenarios;
Ops Concepts;
Functional standards (compression, time  correl & exchange);
Security algorithm;
Various APIs (SLE & others); SOIS MTS (API);

Cross support services (sle, csts); CSS SM;
SM&C (Mission ops svcs, common, core);
Info Arch svcs; SOIS abstract svcs;
SANA;


Protocols (rf, range, code, mod, link, network, file/msg, spp, encap);
Space link idents;
Applic Profiles;
OSCP; SM&C (MAL);


CCSDS doc tree;
CCSDS Glossary;
Info exchange stds (nav, XTCE, DEDSL, time code, PVL, SFDU, SM&C COM);
Reference arch / models (RASDS, SLE, CSSA, this doc);
Operational Processes (SCID assign, CA process, OAIS, PAIMAS);


Stakeholders











Concerns











Modeling Techniques











Analysis Methods












































Based on this table, you can see that that the functional viewpoint is essential spec'd (at a conceptual level)  to provide a view encompassing  scenarios, use cases, operational concepts, and more "format oriented" recommendations.

Similarly, the services viewpoint then identifies a view consisting of the "service oriented" recommendations.

So, in general, the proposal to have services identified in the functional view, is, to me, taking a bit too much of "shortcut" by assuming that we are doing a services architecture, when in fact we really need to address the whole of CCSDS with the Reference architecture.

I do agree very much that there needs to be an expression of the services inter-relationship, and although we could spec the services viewpoint to include that in the services view, I think we could  just as well treat this from the information viewpoint.

I look forward to discussing this further at the telecon tomorrow.

Best regards,

-Erik
From: Roger Thompson [mailto:Roger.Thompson at scisys.co.uk]
Sent: Monday, March 08, 2010 6:31 AM
To: Barkley, Erik J (317H); CCSDS RA BOF
Subject: RE: [Css-rasg] Updated action items

Please find attached the response to Action #017 below.  I apologise for this being late - I realise that 30 minutes before the telecon doesn't give much time for review in advance.
The "one or two paragraphs" ran to a few pages - but sadly no diagrams (partly because I didn't want to get into a debate on which diagramming standard to use).  I believe this could all be done in UML, which may have advantages in terms of tool support to ensure a coherent model.

Best regards,

Roger

________________________________
From: css-rasg-bounces at mailman.ccsds.org [mailto:css-rasg-bounces at mailman.ccsds.org] On Behalf Of Barkley, Erik J (317H)
Sent: 22 February 2010 23:40
To: CCSDS RA BOF
Subject: [Css-rasg] Updated action items

CCSDS Colleagues,

The updated action item list based on today's telecon has been uploaded to the CWE and maybe retrieved via

http://cwe.ccsds.org/css/docs/CSS-RASG/CWE%20Private/ActionItems/CCSDS-RA-BOF-ActionItems-22-Feb-2009.xls

For quick reference the actions from today's telecon are shown below.  Please note that there is a general action to review Leo's synthesis at scenario identification terms.

Best regards,

-Erik

-----Actions from Today's Telecon----

017

Open

Provide a paragraph or two on concerns, issues of functional vs. service view.  (Service identified in functional view vs. service view indicating service relationships)

R. Thompson

22-Feb-10

5-Mar-10



018

Open

Review results of AI 012 (aggregate CCSDS scenarios) and provide comments as needed

All

22-Feb-10

26-Feb-10





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