Embrace uncertainty and go MoSCoW. You don’t have all the answers, and every project is a leap in the dark. So agree on high level requirements based on ‘Must have, Should have, Could have, and Won’t have’ rather than granular fixed-scope, fixed-cost arrangements which always end in tears and acrimony.
…n because there isn’t an economic motivation to create content that people only see when they fail. But failure states happen all the time with data visualization applications, as Susie noted in her comments about annotations becoming irrelevant or out-of-scope for an ever-changing view. An entire class of dashboards is focused not on insights to make better business decisions but on what’s going wrong and where and how badly.