What, exactly, happens when you try to delete a model in A360 Collaboration for Revit (C4R)?
Although C4R appears to be a single system accessible by multiple interfaces, it is actually two different Cloud services, which interface with cached models. As a result, deleting models is not always a straight-forward process. The same is true for undeleting models. Let’s look a bit under the hood, and consider how this affects workflows and backups.
C4R appears as one entity to users, but it is actually two distinct Cloud services: the A360 servers, and the Team Hub server. When the users are operating in Revit, including opening models, performing Sync With Central (SWC), or operating the Manage A360 Models function, they are interacting with the A360 layer. The local cached copy also interacts exclusively with the A360 layer. The Team server is accessed via the web browser, or the mobile A360 app. When you use the Publish function, you are copying the most recent SWC from the A360 layer to the Team layer.
Deleting in the Team Hub is fairly straightforward. Navigate to the Project, and select the down-chevron for the model, and select Delete.
Deleting a model on the A360 layer can only be performed in Revit. First, go to the Communication tab, and select Manage A360 Models.
Select the Project:
Browse to the model, click the Actions button, and select Delete.
You’ll get a confirmation dialog:
And finally, a notice that it’s deleted.
This structure affects deletion in several ways:
- If you delete a model via your Team Hub, it will remain on the A360 servers. A model deleted that way will still be accessible via the Revit application (A360 layer).
- Deleting in Team will also wipe out all Published versions. These cannot be retrieved.
- If you delete a model via the Manage A360 Models function, it will remain on the Team server. This should not affect Published models.
- Deleting a model via either the A360 server or Team Hub will not delete any copies in local user caches.
It is critical note that at this time, Autodesk does not currently offer an undelete function for C4R. (It is likely this will be added at some later date.)
It is also critical to remember that anyone who has access to a Project can delete models in that project.
If someone does delete a model, it should still be available in user caches. Autodesk describes the process for locating your cached models at the following page: Collaboration for Revit: Finding local copies of files
Although it is fairly easy to retrieve models from a local cache, this is not a reliable backup strategy. Therefore, we strongly recommend that your firm establishes a process for creating offline copies of your models in C4R. One recommended workflow is:
- Publish your models frequently (at least once per day).
- Once a week, someone (preferably a BIM manager or IT) should download an offline copy of all models stored in C4R.
- The responsible person should make sure that if they are unavailable, or out of the office, that someone else takes over the responsibility.
- Store the downloaded models in a location where they can be caught by your normal backup procedures.
If Your Model Gets Corrupted
Although C4R is a robust environment, corruption can happen on a sync. As with any other Revit model, poor network communication can interfere with a sync, and cause issues with a model, typically errors on sync, or an inability to Publish a model.
In those circumstances, we recommend the following workflow.
- Try to Publish the most recent STC.
- If you can Publish it, then download it, and try to open it offline with Audit.
- Review additional maintenance steps per our guidelines, available here: Revit Maintenance Guidelines
- If you cannot Publish it, or cannot open it offline, then roll back to the next STC. (Note: This will permanently delete any more recent STC versions that have not been published.)
- After rollback, Publish that version. Download, and try to open it offline with Audit.
- Repeat this process until you have a local model that can open in Revit.
Update: Autodesk appears to have changed the behavior for deletions for C4R.
From what we are seeing, deletions in Manage Models will remove the model from both C4R (Revit) and Team interfaces. However, deleting a model in Team will not necessarily remove the model from the C4R (Revit) interface.
As such, we recommend as a best practice that you always check both systems when making deletions.
Autodesk KB article on C4R data deletion and retention: Autodesk: Data deletion and retention policies with C4R
Microsol blog on Backing Up A360 C4R Models
And our Comprehensive Guide to Setting Up A360 C4R
If you have questions about these procedures, please email us at firstname.lastname@example.org or by phone at 888-768-7568.