While elaborate enterprise architecture management (EAM) methods and models are at architects' disposal, it remains an observable and critical challenge to actually anchor, i.e. institutionalize, EAM in the organization and among non-architects. Based on previous work outlining design factors for EAM in light of institutional theory, this work discusses the theoretical grounding of respective design factors and proposes measurement items for assessing the institutionalization of EAM in organizations. The work identifies measurement items for the factors legitimacy, efficiency, stakeholder multiplicity, organizational grounding, goal consistency, content creation, diffusion and trust, contributing to evaluate and inform EAM design from several, partially new perspectives.