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I do not recognize this description of RMIMs as modifications to the HL7 RIM. RMIMs express constraints on the HL7 RIM - the RMIM is a static model that is defined as a constraint on the RIM, with all the semantics defined in the RIM and associated vocabularies. There is NO additional semantics introduced in the refinement process, just a restriction on the set of conforming structures. It is true that the HL7 XML ITS uses the association names from the RMIM for the XML element names, as a pragmatic choice to aid implementation. It would be perfectly possible to write an ITS that used the underlying RIM association names. This was considered and felt to be less useful by those doing implementations I am yet to see an openEHR XML ITS for instance data, but am sure that a similar implementation trade-off between serializing the underlying reference model or serializing based in the archetype definitions would be worth considering All the best Charlie Charlie McCay, charlie at RamseySystems.co.uk Ramsey Systems Ltd, 23D Dogpole, Shrewsbury, Shropshire SY1 1ES tel +44 1743 232278 / +44 7808 570172 skype: charliemccay linkedin:charliemccay From: [email protected] [mailto:openehr-technical-bounces at openehr.org] On Behalf Of Sam Heard Sent: 06 February 2008 20:29 To: For openEHR technical discussions Subject: Re: Formal methods for Evaluation of Interoperability &Maintainability? Hi Koray I think we will have to come up with some metrics that are relevant as it has not been done before in the domain space. Clearly modelling at two levels is a common approach - relational databases model the idea of tables with rows and columns, linking keys, data types and indexes. The domain information is expressed in terms of these rows and columns. Many systems driven on metadata do the same thing. What is new about openEHR is a generic approach to allow any base model to be constrained through the use of ADL. The result is that the base model can reflect the general business rules and the fixed information constructs - the archetypes the domain knowledge and how it is represented in terms of the base model. The approach relies only on getting sufficient expressivity at the base level to make the split efficient and safe. The comparison in health care at present is with HL7 version 3. This has a base model (RIM) from which a new model, an RMIM, is constructed (level 2). The difference is that RMIMs are constructed with alterations to the RIM classes (which are renamed). So we now have a new class based on a pattern. The semantics of the RMIM is a mixture of RIM and RMIM and difficult to untangle. CDA is using templates in the same way as openEHR uses archetypes - to express some domain content. As CDA is already committed to XML, the means of further constraint is limited - hence the use of schematron and other devices. I guess the first metric that we could consider is the speed at which domain concepts can be modelled and the level of human intervention for documentation and maintenance. The UK NHS, which has the most experience of both, has found openEHR far more efficient to use than MIF template constraints on HL7 CDA. Vendors are cautious and have little experience of openEHR directly as yet. Clearly archetypes are of great use in systems that use the openEHR Framework and allow use of operability constraints out of the box. What about other vendor systems? Well, Ocean tools are being used to produce inputs for vendors which are formal specifications of data to be stored and communicated. The ability to reuse these artefacts for many purposes - queries, transformations, display and data entry provides another metric that is of use. We will need some large systems built on openEHR and traditional approaches to compare in the future. For the moment, just having clinical specifications that are computable is the main influence on choosing openEHR - or starting from scratch as new vendors see the benefits (or not). Cheers, Sam Koray Atalag wrote: Hi, I want to learn how we can formally/objectively prove that Archetype based dual level development formalism alleviates problems of interoperability and maintainability. I was wondering if someone did or know of any such study which applies formal validation methods? Best regards, Koray Atalag, MD, Ph.D. _______________________________________________ openEHR-technical mailing list openEHR-technical at openehr.org http://lists.chime.ucl.ac.uk/mailman/listinfo/openehr-technical -- Dr Sam Heard Chief Executive Officer Ocean Informatics Director, openEHR Foundation Senior Visiting Research Fellow, University College London Aus: +61 4 1783 8808 UK: +44 77 9871 0980 -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.openehr.org/mailman/private/openehr-technical_lists.openehr.org/attachments/20080207/4ddae87e/attachment.html> -------------- next part -------------- A non-text attachment was scrubbed... Name: image001.png Type: image/png Size: 4972 bytes Desc: image001.png URL: <http://lists.openehr.org/mailman/private/openehr-technical_lists.openehr.org/attachments/20080207/4ddae87e/attachment.png>
