Scenario:
1 online shop running on multiple platforms:
there are common functionalities but platform specific too.
Which is the recommended approach to handle this scenario? Can be a backlog for common functionalities and sub-backlogs for platform specific features? Do we have 1 or 4 products?
Of course, you have one product because you have shared parts, that means you have shared resources, scope and other objectives, therefore, they would have a strong relationship with each other. So the best practice in your case is to have one backlog and one working process for all your tasks.
To differ them, you can:
You can create sub-backlogs too, but I don't recommend this because it depends on your working process, so you should answer those questions for decision making:
For me it's one and the same backlog and one and the same product and I assume you have all the items in the same roadmap. There should be also backend part, which is shared by apps, e.g. API. To clearly see the dependencies(e.g. 'need this endpoint to update email from the app') it makes sense too keep all the issues under one roof. Also most likely you'll release one and the same feature simultaneously(or with a short interval) for all the platforms, which makes Business Analyst work by a feature, and not by a platform. But sure it' mandatory to tag or to label or to somehow mark to which platform each issue is related.
Product backlog items will initially contain all requirements as a user stories, and we know that the user story is high definition of each user requirements, in addition there will be a test cases design for each platform requirements, every test case will check the happy and bad behaviors for the application, which may lead to specific test-environment configurations for each platform. as "Tanya R" said, you can "add a prefix in the name of the task, for example [Desktop]". make your development driven by user acceptance test, imagine what these test would be, surely end-user will verify for his android, ios... ,so make that verification as a requirements in the PBIs.
