A variety of reference models such as CMMI, COBIT or ITIL support IT organizations to improve their processes. Although these reference models (RM) cover different domains they also share some similarities. There are organizations that address multiple domains and want to use different RMs. As RMs may overlap in some processes, an approach to compare parts of RMs? procedures which is based on a common RM integration model and on similarity metrics is needed. This approach should enable organizations to efficiently adopt and assess multiple RMs resp. their adoption by automatically identifying commonalities and specific details of the different RMs.