I still work with #UseCases now & then. I am reminded that they can be applied in an iterative way very effectively on non #agile projects
I am working with a client right now that is using a waterfall approach, but that doesn't mean we can't apply some #lean and #agile principles and practices.
First I might just create the use case overview model. Then add actors. If you level your use cases correctly they can aline with #EpicStories, I sometimes still use the Use Case model to identify high level functionality when working on #Agile projects.
Maybe then just the main flows for each use case as the scope solidifies. As more is learnt we can start to add the alternative flows to the use cases that deliver the highest business value.
I have found that writing a fully dressed up use case in one sitting is usually a #wasteful activity as everything on a project can change, so why not build your use cases iteratively using a #justintime approach.
Remember that all the tools and techniques that analysts used before Agile became popular can still be used on Agile projects just in a different way in different sequences and everyone in the team can use them not just the person with the core skill in #BusinessAnalysis.