Hi David, That is clearly a revision change1.0->1.1 but is not a breaking change for data already carried within the system i.e queries for tilt using the degree symbol will still work.
This is is not inherently any different from the situation where we can add codes to an internal codelist, e.g mild/ moderate/severe/ => mild/moderate/severe/fatal This is considered a non-breaking change since existing data is not invalidated but could cause exactly the same kind of potential mismatch between systems using different minor revisions of the same archetype. Revision changes can only guarantee that existing data is unaffected but cannot ensure that mis-matches occur between disparate systems using different profiles on the same archetype. This can happen even with existing archetypes e.g the temperature archetype which allows variations of unit. In practice we need to use some form of templating or profiling to resolve these kind of potential variances in real systems and data exchanges. The good thing in your scenario is that the recipient system would through a validation error, alerting the recipient that an unexpected unit was being sent. I don't think there is a problem here. We expect similar variance issues to arise in other circumstances. Ian Dr Ian McNicoll mobile +44 (0)775 209 7859 office +44 (0)1536 414994 skype: ianmcnicoll email: [email protected] twitter: @ianmcnicoll Co-Chair, openEHR Foundation [email protected] Director, freshEHR Clinical Informatics Ltd. Director, HANDIHealth CIC Hon. Senior Research Associate, CHIME, UCL On 19 October 2015 at 11:45, Thomas Beale <[email protected]> wrote: > > Hence my earlier proposal... > > On 19/10/2015 09:18, David Moner wrote: > > > > 2015-10-16 3:22 GMT+02:00 Heather Leslie < > [email protected]>: > >> · It means that new implementers can use the corrected v1 >> revision and we don’t have to create a v2 for a relatively trivial problem; >> existing vendor implementations can remain unchanged or they can choose to >> update the units if they please. The MD5 changes, but all paths etc are >> identical. A minimal disruption approach, if you like – thanks Heath. >> > > And what happens if a new implementation sends data to an old > implementation? Since the archetype identifier has not changed the receiver > will use its own archetype to validate the received data, and if it > includes the 'deg' unit it will just fail the validation. Breaking > revisions are not only about changing the archetype structure, but also > about generating a different set of possible instances. > > > > _______________________________________________ > openEHR-clinical mailing list > [email protected] > > http://lists.openehr.org/mailman/listinfo/openehr-clinical_lists.openehr.org >
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