SWIM Supporting Material
FAQ - Semantic correspondence
This page contains a set of frequently asked questions concerning semantic correspondences.
Before you begin
Before you begin you should know:
- This page builds on the content found in the Guidance on semantic correspondence section of the SWIM Information Definition Specification Handbook. In particular, the SWIM-INFO-014 Forms of semantic correspondence and Understanding and recording mappings pages explain:
- how best to start the semantic correspondence exercise
- how to record the outcome of the semantic correspondence exercise.
- The ATM Information Reference Model (AIRM) can be found on its dedicated webpage: www.airm.aero. This AIRM is available in various formats including UML and a web-based AIRM Viewer.
- The Resources for information definitions page contains examples and other resources to help you.
- The Get into SWIM presentations give a general overview of some of the items discussed here.
When do I create semantic correspondences?
You may need to build a set of semantic correspondences when, for example,:
- creating information exchange requirements
- creating a service payload
- creating/maintaining an information exchange model
- aligning semantics between the AIRM and a local model/vocabulary
Who creates semantic correspondences?
In general, the work is carried out by an Information/Data Architect working with the appropriate experts. However, there is no real rule on who has to do the work. For example, operational experts may perform the work when building information exchange requirements.
The roles mentioned here are further explained on the Service Orientation Process page of the SWIM Supporting Material confluence site.
What support is available?
The SWIM Information Community of Interest (SITCOM) provides a platform for discussion on all aspects of "information" within SWIM. You can request to join it at: swim@eurocontrol.int.
What do I use when building semantic correspondences?
You will use:
- your information definition
- the ATM Information Reference Model (AIRM)
- the SWIM Information Definition Handbook v1.0
Are example information definitions available?
SWIM-INFO-001 Need for information definitions gives example snippets of information definitions in various formats.
What do I produce?
The main product is a set of semantic correspondences. These can be embedded into your information definition or in a standalone semantic correspondence report.
During the creation of the semantic correspondences you may also produce:
- AIRM change requests (see questions related to this)
- change requests to an existing information exchange model
Are example semantic correspondences available?
The Example information definition shows how semantic correspondences would look in several of these formats e.g. XML Schema, spreadsheet and in tabular data catalogue format. The example is generic and based on a fictional service.
You can find the published version of various semantic correspondence reports at: https://airm.aero/developers/semantic-correspondences.html
- AIXM 5.1.1
- AMXM 2.0.0
- FIXM 4.2.0
- ICAO WXXM 3.0.0
Where can I find the semantic correspondence reports for the exchange models?
You can find the published version of various semantic correspondence reports at: https://airm.aero/developers/semantic-correspondences.html
How are the semantic correspondences created?
The Understanding and recording mappings page gives advice on how to create the semantic correspondences.
How are semantic correspondences assessed?
The author of the semantic correspondences is expected to perform some form of self assessment. The Verification checklist should be used as "The organisation or person responsible for the information definition is expected to complete the checklist. It is then possible to attach the checklist to the information definition as evidence of conformance."
Governance related processes/requirements and regional/national regulations may also need to be met. However, these are not in the scope of this guidance.
What do I do with the semantic correspondences once I am finished?
SWIM-INFO-001 Need for information definitions contains the following note:
... the need to make information definitions discoverable and to manage them properly is well acknowledged. It is therefore hoped that an information definition is open and accessible to the wider community and managed/governed by a well-established group.
This results in needs for discoverable and well-managed semantic correspondence statements. How this is achieved depends on the circumstances outlined in the "Who creates semantic correspondences?" section above, e.g:
- when "creating information exchange requirements" the results may be made available in an enterprise architecture repository
- the SWIM Registry allows for the registration of service definitions and service descriptions. The SWIM EUROCONTROL Specification for SWIM Service Description contains a requirement on semantic correspondence for the service payload model. This means a service description can embed the semantic correspondences or include a link to a place where they can be found
The AIRM Community Area can be used to store semantic correspondence reports. If you would like a report to be uploaded to the AIRM Community Area please send it to airm.secretariat@eurocontrol.int.
When will I need to update the semantic correspondences?
Semantic correspondences are always valid to the version of the AIRM that was used.
However, you may decide to update them if:
- a new version of the information definition becomes available and/or
- a new version of the AIRM is released and/or
- an update to the semantic correspondence requirements occurs
An update to the AIRM may have occurred due to change requests that you have created. See the questions related to change requests for more information on the change request process.
How do I update the semantic correspondences if the AIRM changes?
Each new release of the AIRM is accompanied by release notes that detail the changes made compared to the previous release. The release notes are structured and help you to analyse the impact on your semantic correspondence.
The minimum impact will be a need to update the version number contained in the AIRM unique identifier used as the "target" of the trace.
However, it is possible that the AIRM will have renamed or moved concepts. The release notes will highlight these in order to ease the process up updating your traces. It is hoped that tooling support will become available to automate the migration of semantic correspondences.
Once you have updated the semantic correspondence you should notify the community and make the updated version available, See "What do I do with the semantic correspondences once I am finished?"
I need to write information exchange requirements, how do I use the AIRM?
When you are documenting the information exchange requirements you should use the AIRM concepts. You should analyse the identified information exchanges to see if the concepts can be aligned with the AIRM. This will lead to information exchange requirements that use the AIRM semantics. The AIRM Viewer can be used to find concepts in the AIRM.
You should also raise any AIRM change requests that are required. This could be, for example, when a new information exchange is identified and the AIRM does not already cover it.
For more details see:
- The Service Orientation Process
- The guidance given on the Understanding and recording mappings page.
- The Get into SWIM presentations provide an example on how to ensure the alignment
I am creating a service payload model, how do I use the AIRM?
The approaches mentioned below are discussed on the /wiki/spaces/SCOI/pages/59606150 page. In particular it gives help on Deciding to use an exchange model.
I have used a published information exchange model, how do I point to its semantic correspondence report?
You can satisfy the requirements of SWIM-SERV-290 Information definition - minimum by making reference to the published model's existing semantic correspondence report.
At the moment, several semantic correspondences reports are available on the AIRM Community Area. See http://airm.aero/community.html for guidance on how to join the community.
I have used an extension to a published information exchange model, what do I need to do?
You can satisfy the requirements of SWIM-SERV-290 Information definition - minimum by making reference to the published model's existing semantic correspondence report. You can also make reference to any semantic correspondence report that covers the extension.
However, it may be the case that no semantic correspondence report is available for the extension. The guidance for SWIM-INFO-013 Establish semantic correspondence, states "if the service payload has additional constructs with respect to the exchange model, the semantic correspondence document must be created for the additional constructs." In other words, you may have to create the semantic correspondences yourself.
You can also raise change requests for the published information model to adopt the new constructs.
I have an existing model, but no report, what do I do?
You will need to ensure that the semantic correspondence required in order to prove AIRM conformance in line with SWIM-SERV-290 Information definition - minimum has been completed.
I have used the AIRM to create a model, what do I do?
You will need to ensure that the semantic correspondence required in order to prove AIRM conformance in line with SWIM-SERV-290 Information definition - minimum has been completed.
However, you should maintain the AIRM metadata when you do your modelling. This includes e.g. the unique identifier for each concept in the AIRM. Therefore, when you complete your modelling, the semantic correspondence are inherited by default. This will, obviously, meet the requirements of the specifications.
I have created a service payload model "from scratch" without using the AIRM as the base, what do I do?
You will need to ensure that the semantic correspondence required in order to prove AIRM conformance in line with SWIM-SERV-290 Information definition - minimum has been completed.
I have an information exchange model I would like to make available for reuse, what do I do with the AIRM?
You will need to develop and publish an AIRM semantic correspondence report for reuse. In addition, the semantic correspondences should be maintained by a relevant authority such as the change control board responsible for the information exchange model.
See:
- "What do I do with the semantic correspondences once I am finished?"
If I need an AIRM change request how do I create it?
The process for raising a change request is explained at http://www.airm.aero/community.html. In short, you will have to become a member of the AIRM Community and raise the change request using the AIRM Community Area. A template exists to make the administrative process as easy as possible.
Where do I find the list of AIRM change requests to ensure that I do not duplicate it if using that semantic correspondence option?
At the moment, the list available on the AIRM Community Area. See http://airm.aero/community.html for guidance on how to join.
Do I update the semantic correspondence after the change request is approved?
Once the change request has been approved, the relevant semantic correspondence statement may be updated to one of the other three forms of semantic correspondence. However, this will mean the entire set semantic correspondence statements should be updated to ensure they all refer to the same version of the AIRM. See "How do I maintain the semantic correspondences?"
What do I do if my AIRM change request is not approved?
Your current semantic correspondence is still valid if it refers to an AIRM change request.
However, if you had intended to update your semantic correspondence once a new version of the AIRM is available, you will have to resolve this issue.
The AIRM change control board will give reasons for the rejection of the change request. It could be that the concept is out of scope of the AIRM. In this case, updating the semantic correspondence is relatively trivial.
However, if the concept is in scope, the rejection decision of the AIRM change control board will include ideas on how to improve the current change request so that it can be approved at a subsequent meeting. You can then update the current change request or, indeed, create a new one if you decide to solve the problem in some other way.
Status: Living Material