Where can I find out more about the Rumbaugh Method?
Details of the Rumbaugh method, more formally known as the Object Modeling Technique (OMT), are contained in the following two books:
[Rumbaugh 1991] J. Rumbaugh, M. Blaha, W.
Premerlani, F. Eddy, and W. Lorensen,
Object-Oriented Modeling and Design,
[Rumbaugh 1996] James Rumbaugh, OMT Insights: Perspectives on Modeling from the Journal of Object-Oriented Programming, SIGS Books (Cambridge University Press), 1996.