I think requirements and design documents are necessary for any project of a certain size. In my organization we try to do this for a project that will take a f

I think requirements and design documents are necessary for any project of a certain size. In my organization we try to do this for a project that will take a few Sprints. A Sprint is 2 weeks. The requirements and tech design don't have to be perfect, and they can be updated, as time goes on. If updates are signficant, then we point that out, and adjust deadlines. The nice thing about this is you have a document that describes what we built, and another document which describes how we built it, at the end of the short project. We scope these projects so they can fit into a quarter. If it's longer than quarter, we try to break it down by certain milestones. I also don't like User Stories, maybe it's just how they are set up in JIRA, but once you have the tech design, it's pretty easy to break it down into tasks. This mostly works for my company.