The design and ongoing management of an Enterprise Architecture is widely accepted as an established way of managing an organisation’s complexities in relating business and Information Technology capabilities. While the focus of related research is predominantly on frameworks, tools and methodologies, only limited attention has been given to understand and improve the value realisation process of Enterprise Architecture. We adopted the DeLone and McLean model of IS success for the design of a value realisation model specific to Enterprise Architectures. Thereby we identified service quality and actual use as two major catalysts fostering an Enterprise Architecture’s overall success. The amendments made were based on findings from two major case studies involving an Australian utility company and a Swiss insurance company.