Enterprise architectures (EA) embody the business objectives, processes and information technology infrastructure reflecting the desired incorporation and standardization requirements of a company’s operating model. It is vital that during the initial design stages the software system’s architecture aligns with the EA. While frameworks exist to check the alignment of enterprise and system architectures, there is an assumption of well-defined requirements derived from the EA’s business objectives. This transition is non-trivial as the EA can be a significant document representing the viewpoints of the stakeholders. This paper proposes and illustrates, using the Grounded Theory Methodology, a systematic, qualitative procedure, to extract the functional and non-functional enterprise requirements from the EA and/or system description. The contribution of this work is to further systematize the alignment and traceability of EA and system architectures and provide the initial requirements and system models necessary for supporting the of enterprise systems.