In one respect this book is a classic because it is frequently referenced in the body of literature on IS/IT management and IS/IT strategic planning. Out of the past 50 or so articles on the topic (including corporate and city/state/Federal government strategic plans, PHd dissertations and white papers) over 75% have cited this book.
This is not, however, a "how-to" book that describes a coherent strategic planning process. It's a collection of standalone chapters on each key element of strategic planning. The material is presented in sequential order, but no single chapter depends on another. Moreover, there is no smooth continuity between the chapters or a master chapter that ties it all together. That said, this book is valuable from two perspectives:
(1) Each chapter is highly focused and contains a wealth of information on its topic.
(2) Used as a collection of mature techniques this book could be used to support an effective strategic planning process.
The main value is the fact that each element of strategic planning is thoroughly covered. I frequently use this book as a catalog of procedures and techniques for numerous projects, including strategic planning, assessment, process improvement and IS/IT organizational improvement.
If you are seeking a book that shows step-by-step how to perform IS/IT strategic planning you may not like this book. However, if you are an experienced practitioner this book is a wonderful resource to which you'll find yourself frequently referring.