Direct references to external AAS or Submodels using ReferenceElements

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This repository aims for providing answers to often asked questions in the context of the Asset Administration Shell.

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Direct references to external AAS or Submodels using ReferenceElements #111

Closed griemens closed 5 months ago

griemens commented 6 months ago

At official FAQs. It states for refencing external sub models

"2. Direct references to external AAS or Submodels using ReferenceElements or RelationshipElements. We currently do not recommend this method in case of lacking generalizability and creation of tight couplings between AAS (by taking over the “resolution” part).)" https://github.com/admin-shell-io/questions-and-answers#id42 https://admin-shell-io.github.io/questions-and-answers/#id42

Is this today still not recommended ?

Thank you for the insight.

StenGruener commented 6 months ago

@griemens is there some particular event, like publication or something else making you re-checking this?

griemens commented 6 months ago

No particular event. Just evaluating in what cases AAS is the preferred choice compared to others like DTDL, iTwinJS schemas, AML. So far I could not find a good description of the motivation for this recommendation, so wondering if is still correct or new insights emerged last 2 years. Note: If external reference is still not recommended it would probably also mean that use cases that requires this, should probably not use AAS.

Thank you for the clarification.

StenGruener commented 5 months ago

Hi @griemens,

i think this is a difference, between "possible" and "recommended":

in case a "tight coupling", e.g., a link into an element of the 'particular' submodel, then its okay.
in case a "loose coupling" is needed, e.g., a link into an element of the 'newest' submodel with some idShort, we reccomend using the de-tour via asset id to enable resolving for the latest aas.

So its not about using external references or not in general, it is about what to point to, i.e., a 'particular' submodel id or a 'resolvable' asset id.