There was a time when we were writing user stories to describe requirements. I’d say they worked fairly well for us. But we don’t do this anymore.
We were using user stories as a technique which allowed us to describe bigger chunks of functionality. There was one bigger sub-project or module and it had more than 10 user stories attached (usually closer to 20) and a handful of non-functional requirements. During development we were often going through several stories at once as technical design didn’t map directly to the stories. The stories were more of input to design session and a base for test cases than stand-alone bites of functionality.
Then we switched to Kanban. One of consequences was we reduced the size of average feature which was going to development. It no longer had 15 stories attached, but it wasn’t a single-story task either. If we were still writing user stories to each Minimal Marketable Feature we would probably have few of them. My guess is 2 or 3 most of the time.
At this level stories become pretty artificial. I mean if you think about 2 stories connected with one feature, i.e. administrator can configure this magic widget and user can use this magic widget to do, well, the magic, you can pretty much tell these stories intuitively in your head. Writing them down becomes overkill.
Besides that I think the often cited role of user stories which make usage scenarios completely clear is overrated. If you can talk with developers in language closer to the code, and functionality description is much closer to the code than telling user story, you’ll be better understood. The standard problem here was that functionality description wasn’t precise and it often became disconnected with usage scenarios.
The answer for this problem is: make features as small as possible (but only as small as they still does any difference). Small features are easy to define, easy to understand (even for a developer) and easy to chew. It is pretty hard to screw them.
There’s one more reason why I don’t consider user stories as a must-have. If you happened to create software which will be used by other developers or administrators at best, like some magic box with a lot of APIs and command line interface as the only UI, you should know what I’m talking about. If you write stories for this kind of software you end up with a bunch of “as a developer I want to call the magic function which does the magic” stories. Doesn’t API specification make more sense?
I don’t say user stories are bad. They aren’t. But they don’t add value all the time and in every situation. This is just another practice which should be used only as long as it does make sense in your specific situation.