Versioning support

Creating a new version

A version is created when the state of a particular terminology needs to be captured. From a business sense it is performed when the terminology is ready to be published to customers. Versioning always applies to the entire terminology and can be performed at any time on the current state of the terminology. For example, the SMOMED CT July 2013 release is a version that marks the state of SNOMED CT at this particular point of time. Different versions are distinguished by tags, hence the process of creating a version is often referred to as tagging. There are no versions of SNOMED CT reference sets, and SNOMED CT map type reference sets since they are considered to be part of SNOMED CT. When a new version of SNOMED CT is created, modifications made to reference sets and map type reference sets are contained.

Versions can be created for all editable artefacts namely:

• SNOMED CT
• ATC
• LOINC
• Mapping sets
• Local code systems
• Value domains

To create a version, verify that all changes are saved. Go to'' Tools > Create'' version, or use the toolbar button to bring up the wizard. Enter a unique version name and a description. If applicable, existing versions are displayed in the bottom section.

Specifying version name and description

Where applicable (ATC and LOINC do not have an effective time property), you can use the calendar icon to specify an effective date. By default the current date is displayed. Click Next.

Selecting a SNOMED CT release

You are now presented with a summary of unversioned components. These are components that were modified since the last publication. Where applicable (ATC and LOINC do not have an effective time property), these components will be updated during the versioning process by changing the effective time from Unpublished to the specified publication date. Components that were not modified will not be updated and keep the original publication date. Click Next to start the versioning process.

Summary of unversioned components

A dialog confirms the versioning was completed.

Confirmation of versioning with version name

Switching between versions

Apart from the latest release of SNOMED CT, Snow Owl now allows to browse and edit older versions of SNOMED CT. You can switch between available versions of LCS, MS, VD, LOINC, ATC.

To select a version, click the icon in the toolbar or select Tools > Select version in the menu. You can see a list of the terminologies and local code systems that are supported in Snow Owl. By default, the latest version is used, which is indicated with MAIN. To work with an earlier version version,

• Click on table to open the drop-down list
• Select the preferred version from the list
• Finish.

Selecting a SNOMED CT release

You can verify that you are working with the selected release by opening the root concept in the editor where the information about the version is listed as a synonym. Please note that the tree in the SNOMED CT view might also change, since older SNOMED CT releases had different top-level concepts (e.g. Disease used to be a top-level concept).

SNOMED CT root concept from July 2006 release

The status bar on the bottom now has been redesigned to indicate the current version of the artefact the user is working with. There are two scenarios:

1. User is working on a task - the status bar displays the task name (with a link to the task editor) as well as the context of the task (Terminology and version). If you hover over the task icon, you can see additional information about the task (number, name, context, scenario).
2. User is not working on a task - "No task activated" text is presented and status bar displays the version of the currently selected artefact.

Tooltip displaying additional task information

History view: Concept history by version

The history of a concept is now grouped by releases. If you click on a version, you can see which changes were made in a particular release of SNOMED CT.

Concept history grouped by version

Commit information update

New information has been added to the commit information view. It's now possible to see the terminology, and also if the work was performed on MAIN or on a branch.

Commit information view

Value Domain and Mapping Set members

Members of Value Domains or Mappings now incorporate versioning information when created. When a component is added to a Value Domain or a Mapping Set the following rules apply:

• If the component has never been versioned the member version is set to "Unversioned"
• If the component has been versioned
  • and changed since the last versioning, the member version is set to "Unversioned".
  • not changed since the last versioning, the member version is set to the last version tag.

SNOMED CT versioning support for import

Import options have been restricted depending on the existing data in Snow Owl. This means that import options that are not suitable will be disabled (see screenshot).

• The Delta release contains modifications since the previous release and are used to update a previous version of a full release. For this reason, they can only be imported if there is already SNOMED ED CT content in Snow Owl.
• The Snapshot release file contains the most recent version of every component without any historical information. It can be imported in an empty database or if there is already an older SNOMED CT release.
• The full release contains every component and every version ever released. An import is only possible if there is no SNOMED CT content in Snow Owl.
• Create versions for each effective time: This option is only available when importing a full release. It creates a separate version for each release, which allows to switch between versions, for example if you want to work with older versions. If you run the import without creating versions, you will still be able to see historical information in the History view, but won't be able to switch between versions.

SNOMED CT import

Simplified export

Due to the newly introduce version function, it's not necessary to update components during export anymore. Only the current state of the content is exported, there is no content modification during export. This means that unpublished components remain unpublished, and published components retain their publication date.

The export wizard has been simplied. To run an export

• Verify that you saved all changes
• Go to File > Export > Snow Owl > Select the artifact type you want to export (e.g. Value domain to Excel)
• Hit Browse to specify the file name and file path. Click Next to start the export

Specifying file name and file path for export

After the export, you can find a link to your export file.

Link to export file

If you want to create an official release, you need to update the effective time of unpublished components by creating a new version. Afterwards, you can export the new version.

To export an older version

• Switch to the older version (Tools > Switch version)
• Verify that the selected version is displayed. The version is indicated in the statusbar on the bottom.
• Now you can export the file as described above.

Documentation

A new chapter about Versioning was added to the Snow Owl User Guide guide.