I'm throwing this out and maybe I'm lucky or it will just lead to a bunch of crazy stuff.

I got this question a few time now from some customers. 

My answer today is: "Check the logs, click around, and of course you do this in a test environment."

It's regarding a checklist after upgrading the product. Like a "post-upgrade checklist".

I know that the logs are telling a bunch of stuff and messages like "successfully upgrade".

What I'm asking for is more a checklist the customers can go through after they been successfully upgraded.

Example:

- Verify that e-mails is still coming in.

- Create an Change Request to make sure the workflow is still working.

- Go through solutions and check that attachments are still available.

Or maybe something else...

Maybe some of you have a really good workflow for this and wanna share.

All the best!