Although many might tend to limit the concept of agile requirements to "user stories", this book reminds us that there could be more than just a post-it on an information radiator when we talk about requirements. The title of one of the initial chapters is "The Big Picture of Agile Requirements" and this book provides it, together with the small details that can help you write better stories.

Dean Leffingwell describes the general context of managing requirements in organizations based on a three levels view: portfolio, program and team. The concept of requirements is different at each of these levels: from the investment themes and epics of the enterprise strategy to the user stories implemented by teams during Scrum sprints. An interesting concept developed in the book is the Agile Release Train (ART) that aggregates user stories in features set. The goal is to adjust the team's capacity to produce software with the ability of customers to absorb it.

The book is very well written, achieving balance between a structured approach and easiness to read. It contains many case studies, templates and sample agenda that help relate the ideas expressed with the daily activities. Three appendixes at the end propose interviews and document templates, along with a release-planning checklist.

This book provides a detailed and extensive study of the agile gathering and management of requirements in enterprises and I will recommend it to everybody involved in some software requirement activity, from the business analyst to the project manager or developer.