Reference Models allow the verification of existing components of a model and how these components relate to each other, giving a high-level idea of how the model works. The Reference Models have many uses; most importantly, we can map them with more specific organization models (Concrete Models), and use this mapping to verify what kind of changes need to be done to adopt new standards and practices, like CMMI. The purpose of this paper is to show how CMMI DEV version 1.3 Reference Model can be useful for organizations who want to adopt it by using a Portuguese company that is adopting it as a case study.