In some of my book that I read about scrum in agile, all things are uncertainty process. I learned that in a process of agile the project methodologies that trying to predict the future too far in advance can have disastrous results. As an estimate of completion, not a committed timing for delivery. But another way scrum showing real results really quickly but is not immune to the usual challenge faced by every project
the book covers lots of case studies and is a good book for PO (product owner) and product manager to read. I learn that have a logical thinking is to understand the process first and then asking next. In my experiences, the process agile is really different when I work in many start-ups company in Indonesia, the agile process sometimes not have direction roadmap but sure the business requirement is priorities.
Even the business is not that necessary into the process development because the iterating for make the product value is important. What I trying to say that business needs to understand the challenge more deep to make the minimum valuable product work in the market.