Working with customers and in the Jazz.net forum shows there is a strong desire to implement and automate the development processes. Therefore Process customization, especially around work items has always been a major hotspot in RTC adoption. Experience also shows that a lot of the requirements in process customization are driven by process problems and the desire to avoid having to fix the process by customizing the tools instead.
This presentation shows the process customization capabilities available in RTC. It also shows examples for requirements that are hard or impossible to implement in RTC and it shows requirements that might indicate that you should consider fixing the process rather than the tool.