This book is for people handed a request to build a system who want to know what problem they're actually supposed to solve.
When the request already names the thing to build, how do you get back to what needs to change?
Chapter 1 starts with what actually arrives: not a problem, but a solution someone has already chosen.
If you'd rather write down the gap between where things are and where they should be than jump to how to build it, it's in this book.
Three chapters give a repeatable method for turning a request into an actual problem statement: As-is, To-be, and Gap, four axes of scope, and how to hand off to requirements definition.
About 10,000 words, PDF and EPUB, one-time purchase.