The best books about defining software requirements

Suzanne and James Robertson have been writing insightful books on software requirements for many years. This book covers all the important topics, including understanding the real problem, different techniques for exploring solutions, and numerous ways to communicate requirements effectively. I especially like their treatment of quality attribute requirements and defining “fit criteria” to judge whether a solution adequately addresses them.

The book includes a comprehensive requirements specification template to guide writing a rigorous and complete specification on projects for which that is valuable. I also appreciate their use of visual models both to communicate with the reader and to guide the reader in communicating requirements to project stakeholders. I do prefer my book Software Requirements, but this is an excellent choice as well by two authorities in the field.

Exploring requirements is more about communication than computing. Requirements elicitation often involves discussions between business analysts and user representatives or other project stakeholders in either one-on-one discussions or group workshops. Requirements by Collaboration presents a wealth of practical tools and techniques for planning and leading requirements development workshops. It’s packed full of useful tips, checklists, questions to ask, and activities to perform to make workshops effective and successful.

I especially like Gottesdiener’s “collaboration patterns,” eight techniques that a workshop facilitator can employ to help the group achieve its objectives. The pattern called Decide How to Decide is the first one that any group of collaborators should use: exactly how will we make decisions? If you expect to lead, or even participate in, requirements workshops, read this book first.

Most discussions about requirements focus on functionality, which is what the users most obviously observe in a software system. However, user satisfaction also depends heavily on nonfunctional requirements, such as various quality characteristics the system exhibits: usability, availability, reliability, security, scalability, maintainability, and others.

The Quest for Software Requirements is the only book that focuses on nonfunctional requirements. It provides many questions a business analyst could ask during requirements elicitation to understand the stakeholders’ expectations for those all-important quality attributes. That’s an often-neglected aspect of requirements exploration that frequently leads to deficiencies that can be expensive to correct later in development or after the product is released. This book can help you avoid those unpleasant outcomes.

I recognized the value of use cases the first time I used them successfully on a project. Some years later I developed a 1-day training course on use cases. I read four of the most popular use case books then available, cover to cover, one right after the other. Use Cases: Requirements in Context did the best job of presenting a practical approach to applying the use case technique. 

Shifting the requirements focus from system features to a usage-centric viewpoint provides many benefits, and use cases are the best way I’ve found to approach that. They provide an organizational structure for grouping related information relating to how users will interact with the system to perform tasks. This book describes a solid way to apply the use case technique.

Many agile projects employ user stories as a way to represent requirements rather than a more traditional approach combining use cases and functional requirements. I favor the latter approach for several reasons. Nonetheless, user stories are well established in the agile development world, and if you wish to learn about them, there’s no better author to read than Mike Cohn. Cohn describes how to craft user stories well and how they fit into the agile development process.