Developers and QA testers are treated as separate teams at our company, something we are trying to change by adopting scrum. The QA team is distributed globally and each local team has different hardware in order to test platform-specific tweaks we make to our applications. So if we implement a fix required for the application to run on platform X, and QA Team 1 has an X onsite, then they are assigned to validate that particular defect or user story. If we implement a fix for platform Y, that gets validated by QA Team 2. And so on.
The problem is that we do not know ahead of time which platforms we will be developing for, and therefore cannot say ahead of time which QA teams we will need to partner with during a particular sprint. Incorporating all of QA into our scrum team every sprint would make the team huge, with the associated coordination challenges and overhead that brings. We are experimenting with a scrum of scrums that includes representatives from both the dev and QA teams, but that still maintains the current organizational boundaries rather than making us a truly cross-functional team.
How can this process be adapted to scrum?
I understand that kanban might be a better fit for this operational model, but that is unlikely to happen.