I've been getting more and more emails lately from people confused about the difference between “user stories”, “epics” and “themes.” So I thought this month we'd return and cover some basic–but very helpful–territory by explaining those terms. First, the terms don't matter that much. These are not terms with important specific meanings like “pointer” to a programmer or “collateralized debt obligation” to whomever it is that's important. Story, epic and theme are merely terms we use to help simplify some discussions Scrum teams have. The terms do have standard meanings that date back to some of the earliest Extreme Programming (XP) teams. And it's nice to use terms in industry-standard ways. But, if these terms didn't exist, you'd make up your own.
So let's see what each means.
A user story is simply something a user wants. User stories are more than just text written on an index card but for our purposes here, just think of user story as a bit of text saying something like, “Paginate the monthly sales report” or, “Change tax calculations on invoices.” Many teams have learned the benefits of writing user stories in the form of: “As a <type of user> I <want/can/am able to/need to/etc.> so that <some reason>.” But it is not necessary that a user story be written that way. Check out the advantages of that user story format.