User Analysis allows you to get actionable insight about users and their behavior which will inform your UX design strategy.
You need to know your user as a person, understand how and why they’d use your product (and how often), and all the experiences that come between them and your product. That multi-dimensional understanding is the only way you’ll be able to prioritize your features appropriately — otherwise you might enter the Design stage without even knowing you’re on a course for disaster.
For more smart ways on incorporating documentation into the design process, download the Guide to UX Design & Process Documentation. Expert advice is featured from Aarron Walter, Laura Klein, Ian McAllister, and dozens others. Visual examples are also shown from companies like Vurb, MailChimp, Apple, Google, and many more.