I often meet managers trained in the PMBOK and are certified PMPs (Project Management Professionals) who do not know enough about the CMMI but continue to press for using PMBOK as a guide in improving IT project management processes. I have studied the PMBOK and believe that the CMMI is a better option for managing IT projects. I can help PMPs understand my views better if I can show a map of processes in both the PMBOK and CMMI processes and then showing additional features of the CMMI helpful in managing IT projects. I would appreciate it if you could lead me to any such study where the two are mapped, something similar to the CMMI - ISO 9001:2000 map.
Try this link from the SEI http://www.dtic.mil/ndia/2005cmmi/thursday/sherer.pdf, it will pull up a presentation that compares and contrasts the CMMI and PMBOK. In addition, this page http://www.sei.cmu.edu/cmmi/adoption/comparisons.html provides links to a number of comparisons between the CMMI and other models and standards.