Does changing issuetype scheme affect anything?

[Hoc]

Hello,

I see that projects are created with its own issuetype scheme. On our instance, there are a lot of issuetype schemes which has that same issue types. 

Can I add them all to the same issue type scheme to reduce the amount of duplicate issuetype schemes? From what I can see it doesn't affect the field configuration, workflows, screens or the issue layout.

Thanks

[Brant Schroeder · Accepted solution]

You are correct.  As long as the scheme you change the project to has the same issue types in it there will be not impact to the project.  The issue type scheme just associates issue types with the project.  More information can be found here: https://confluence.atlassian.com/adminjiracloud/associating-issue-types-with-projects-776636339.html

[Hoc]

Thanks @Brant Schroeder 

Another question. If I have old projects I no longer use which say has 5 issue types and I assign it to an issue scheme with just 1 issue type. Does it affect the issuetypes on that project other than not being able to create them other than what is available on the issue type scheme?

[Daniel Ebers]

Yes, in case you have a project assigned with an Issue Type Scheme holding five issue types and all of them are in use by at least one issue in your project you can switch to another Issue Type Scheme using just one issue but an migration (for the, at least, four issue types that won't be present in the new Issue Type Scheme anymore) will be requested by a wizard that is presented in cases like this to you.
In case the new Issue Type Scheme defines an Issue Type which was NOT present in the previous Issue Type Scheme with the five Issue Types all Issue Types in your project will be migrated by the wizard.

The wizard let you choose a new Issue Type for each Issue Type that is not included in the new Issue Type Scheme. From my experience this process does not work very well and tend to lead to a timeout (on big instances/operations). Further, there are reports about data loss in some (rather special) scenarios when data cannot be migrated. This overall means, a dry run on a non-production environment would be advisable.

Please let us hear if this answers your question.

Cheers,
Daniel