If you really want to learn how to interpret the environment and make sense out of it, you have found the best resource on the market for it!

Personally, I usually find that the business environment scanning books give too shallow advice and doesn't really explain how to do it. This book is the exception to that, as he explains how and why to do stuff, while at the same time keeping a coherent logic thru the whole book.

Deeply recommended for any manager that perceives that there exists an environment out there, that s/he need to at least understand a bit about.