Questions about the Essential meta model

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dJdU
Posts: 2
Joined: 02 Mar 2009, 21:01

It's very exciting to discover this project!

I am wondering about the meta model. Is there any material explaining and documenting the choices made?

My reasons for asking:
(1) the four layers seem a bit arbitrary; not everyone would use these. Would it be feasible to introduce a more general abstract class "Layer" and let users either apply instances of those (Business, Application, Information, Technology) or define their own more suited to their enterprise?

(2) I note the terms Conceptual / Logical / Physical cross-cut all of the "layers". To me, these seem more like Layers (often developed successively) whereas Business, Application, Information, Technology seem more like "domains" or "areas of concern" (not ordered as implied by "layers").

(3) How easy is it to extend/modify the meta model? I often work within the paradigm of ISO/IEC 42010 ( http://www.iso-architecture.org/ieee-1471/ ) which has its own meta model for architecture description, and want to be able to communicate in that language to enterprise stakeholders.

-- Rich
john.gaul
Posts: 4
Joined: 24 Feb 2009, 11:06

Rich

We’re glad you’ve enjoyed looking at the Essential Project!

I’ve put a couple of links to the meta model information here – http://www.enterprise-architecture.org/ ... meta-model and here http://www.enterprise-architecture.org/ ... meta-model

Regarding the choices made in defining the meta-model, we have a list of topics that we are planning to cover in our Team Blog, and this is definitely one of them. We considered publishing a document in the Documentation section of the site describing the rationale, and in the end we thought it would be better to give members the opportunity to comment on our thinking via the blog. As you can imagine, this is one of a number of areas that we keen to discuss with the community - we can always move it up the list.


To answer your specific questions:-
1. These four layers have come about from our experience of modelling a number of different businesses. We've found them useful and broad enough to cover the architecture management scenarios we've encountered so far. In forming the Essential Project we're hoping to gather the collective practical experiences of the community to take the metamodel forward and so we'd welcome your ideas and any examples and scenarios that you feel go beyond these four layers.

2. Briefly, we do see a naturally-ordered dependency between what we define as the four layers, and the conceptual/logical/physical as different abstracted views of the elements contained in these layers. We'll look to expand on this in the blogs as part of the discussion on the rationale behind the metamodel.

3. The nature of the tool is such that making changes to the meta-model is quite straightforward. Regarding ISO/IEC 42010, our focus up to this point has been largely in the areas we currently identify as layers (i.e. business, application, information and technology architecture) with particular emphasis on Business/IT Strategy Management and Change Management. As in point 1, we're keen for the community to develop additional perspectives (as extensions rather than changes), and would be happy to support members in doing so.

Regards
John (Essential Project Team)
dJdU
Posts: 2
Joined: 02 Mar 2009, 21:01

Thanks for the pointers to additional metamodel materials. I will definitely look at those, and want to try my hand at metamodel extension along the lines of adding the constructs of ISO 42010 (IEEE 1471)!
john.gaul
Posts: 4
Joined: 24 Feb 2009, 11:06

Sounds great. Feel free to post any additional questions or queries that arise - we're happy to help. Please do keep in touch to let us know how you get on.

John (Essential Project Team)
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