This book contains a lot of good guidance on working with multiple suppliers in a service management environment. However, it all seems to apply both to SIAM and non-SIAM environments, so the benefits of adopting SIAM are not clear. In fact, I have encountered everything mentioned in this book in non-SIAM environments, so felt too often that the book was stating the obvious rather than telling me how SIAM actually solves these issues. Hopefully the SIAM Professional BoK will shed more light on this.