I'm getting started with Portfolio for JIRA and plan to create an Initiative hierarchy level because we do work on initiatives that span multiple teams. The documentation says you can create an Initiative issue in your project to live amongst your epics and stories, but Atlassian recommends (or at least strongly suggests) you consider creating a separate project for your Initiatives.
Intuitively, the separate project makes sense to me so I'm inclined to do that. However, not everybody on my team agrees.
What's the case for not creating a separate project for the Initiatives? Or, asked another way, what's the downside to not having a separate project for Initiatives and instead, putting them in your project
I see this as a best practice - depending on the definition of Initiatives within your organisation.
Initiatives are often designed as the largest piece of work - an objective or goal which could span multiple projects and teams all working towards a common goal. Because this Initiative might be at a high level (Program or Portfolio) - you might want to restrict who can edit, transition, move - or even see - the Initiatives.
Having them in a separate project makes it simpler to manage access / edit rights to them. You could also restrict delivery projects from creating Initiatives using issue schemes - to avoid unnecessary clutter being created in lots of projects.
Could you just create Initiatives in your own projects? Sure, but so long as in the most part, you're happy for users with access to it to be able to do as much in your Initiatives as they do in your Stories.