Three schools of thought on enterprise architecture exist, each with its own belief system (definitions, concerns, assumptions, and limitations). A novel taxonomy of these schools creates a starting point for resolving terminological challenges to help establish enterprise architecture as a discipline.

In order to aid organisations in the adoption of enterprise architecture (EA) best practices, maturity models have been proposed in the literature. These models offer organisational roadmaps and assessment frameworks for increasing EA maturity. However, key questions concerning the implied meaning of the term maturity in the context of these models have been left unexplored by previous research. This research, aided by the field of organisational learning, offers new insights into the implied assumptions of current EA maturity models and offers initial concepts and constructs to guide the conceptualisation, construction and refinement of enterprise maturity models.

In some conventional definitions, Enterprise Architecture (EA) is conceived as a descriptive overview of the enterprise, while in other views EA is seen as a prescriptive framework of principles and models that helps translate business strategy to enterprise change. The conceptualizations of EA also vary in scope. There is an increasing recognition of EA as a systemic, enterprise-wide capability encompassing all relevant facets of the organization, transcending the traditional IT-centric view. However, we argue that none of the conventional conceptualizations of EA are adaptive in the face of today's complex environment. We view that an adaptive EA must go beyond a single organization and fully appreciate enterprise-in-environment ecosystemic perspective. Drawing on the heritage of Open Socio-Technical Systems Design and adopting the "three schools of thought" as a meta-paradigmatic backdrop, the paper features four different views of long-time scholar-practitioners, who discuss what an adaptive enterprise architecture would entail. Integration of these views paints a radically reconceptualized picture of enterprise architecture for the future. With this paper, we want to lay a foundation for a debate on the need for alternative conceptualizations, manifestations and research agenda for enterprise architecture.

In recent years, there has been an increasing interest among researchers and practitioners concerning Enterprise Architecture (EA). Despite this increase, several studies have reported a lack of common understanding in EA. Some specific expressions like lack of common terminology, lack of shared meaning and fragmented literature have been frequently used to describe this lack. However, very few systematic studies have been conducted to gain a better understanding about the nature and the extend of these definition differences. This study presents a Systematic Literature Review considering journal articles that contain explicit definitions of EA. 145 definitions were identified and analyzed in order to determine their similarities and differences. The analysis was guided by concepts from the field of terminology. The findings of this study show that there are significant divergences of multiple kind between definitions. The next steps for the EA community would be to achieve something comparable to MacGregor's Theory X and Theory Y model or Mintzberg's schools of thought.