This book has been a core part of my company's methodology for years.
While many of us think of the programmer as an artist working alone, Yourdon lays out a path for taking the work of an individual and turning it into a group product. This is extremely useful when developing enterprise applications, which need to be maintained and enhanced by a group.
As a side benefit, his method is also useful for mentoring younger programmers with the conventions and styles of the older programmers. Yourdon's method also removes management from this process, making sure the walkthrough is about creating quality software and not embarrassing staff.