Ihab Sarieddine has a nice overview of CCPM in his blog on project management, Improving Scheduling Using Critical Chain Project Management (CCPM).
He refers back to Goldratt's original book on the topic, Critical Chain, and gives slightly different definitions of some of the classic reasons projects run short even with plenty of buffer in task estimates: Parkinson's Law, Student's Syndrome, Dropped Baton, Self-protection, Excessive multitasking, and Resource Bottlenecks. (I assume these come from the book, but if not, I like them anyway.)
The article is entitled "improving scheduling" with CCPM. While this is true - scheduling often does improve when I do CCPM projects - CCPM is also a great execution management mechanism with the buffers and fever charts (buffer consumption vs chain completion) giving a means for prioritization and focus to everyone. This gives people early warnings if things are going pear-shaped - and a way to focus on what will bring it back into control.