Negin Banaeianjahromi: In the current business era, it is crucial for an organization to understand the rapidly changing environment of today. To swiftly respond to the changing environment, an organization must provide enterprise integration (EI) not only internally, but also externally, with its customers and suppliers. Many approaches and technologies have been proposed to facilitate EI – however, due to its complexity, integration has remained a continuous challenge in organizations. One of the major integration obstacles is maintaining architectural descriptions of the organization. Architectural descriptions, or Enterprise Architecture (EA), provides a comprehensive view of all the organizational entities and their relationships to achieve an organization’s strategic goals. Many studies have referred to EA as a solution to facilitate EI in organizations. However, developing EA is not easy to achieve. This PhD dissertation aims to facilitate integration projects by approaching EA obstacles from a social and organizational perspective. The main research question is What is the role of EA and its obstacles in EI? A qualitative and interpretive research approach is applied in this dissertation. The data was collected through interviews with practitioners from 17 large organizations and analyzed using the Grounded Theory method. The study first investigates the EI obstacles and identifies EA maintenance as a major obstacle in EI projects. After identifying the EA obstacles, the dissertation further investigates them to understand the issues in EA development that prevent EA from being efficient. By investigating the obstacles in EA development, this research shows that if not addressed properly beforehand, the obstacles follow EA through the development process. Most of the identified obstacles are social and organizational issues. The results indicate a ‘lack of communication and collaboration’ as the root obstacle in EA development that can address most of the other obstacles. Revisiting the data from a communication and collaboration point of view, the results reveal ‘organizational culture’ and ‘clarity in EA development process’ as additional causes of the lack of communication and collaboration in EA development. Furthermore, ‘personnel’s distrust’ and ‘organization loses its competitive edge’ are identified as additional effects of the lack of communication and collaboration in EA development. Finally, this study provides some recommendations to facilitate EA development for researchers and practitioners.