Jez Humble says that last mile between development completion and production can be expensive and painstaking because teams aren't always prepared for it. His book discusses the importance of making sure that everything you check-in to version control gets built, run through test automation, and deployed automatically to all of the necessary environments. These tools also keep all stakeholders in the software's production involved.
Jez Humble is the Build and Release Principal at ThoughtWorks Studios. He manages the Cruise product, which covers build and release automation in TWS's tool suite. Humble also talks and consults around build and release management. Later this year, Humble will release his book on these subjects.