Changing Workflow for a highly active project

[Denise Schiller]

If I want to update the workflow for an active project with hundreds of stories and issues, are there ramifications to updating the workflow?  Attached are images of the current workflow (built by someone else) and the proposed workflow to show the waterfall process of the workflow. 

[Joe Pitt]

I do all my workflow updates after hours or on weekends when people aren't working. There is always a chance someone may be in the middle of something you are changing and results are unpredictable 

[Jack Brickey]

being safe is rarely a bad thing!

[Nic Brough -Adaptavist-]

I think more recent Jira versions handle it better, but you used to be able to create the "cannot transition an issue, no matter what" problem if someone transitioned an issue while you were applying a large migration that changed transition destinations or removed status.

Having said I was able to track it to that, it's been twice in many years, and not recent.