A pattern based methodology for analyzing enterprise architecture landscape Jihane Lakhrouit 1 , -Karim Baïna 1 1 University Mohammed V, ENSIAS Alqualsadi research team on Enterprise Architecture Rabat, Morocco Abstract Nowadays, enterprise architecture (EA) has garnered considerable attention from both practitioners and academics in the fields of information systems and business management. Enterprise architecture (EA) is an approach to managing the complexity of an organization’s structures, information technology (IT) and business environment, and facilitating the integration of strategy, personnel, business and IT towards a common goal through the production and use of structural models providing a holistic view of the organization. In this paper, we present a complete pattern based methodology for evaluating the complexity of enterprise architecture. Our objective is to propose an evaluating methodology for guiding designers and architects in evaluating and improving the EA models. Furthermore, our enterprise architecture patterns system will be used for an automated support so as to manage the evaluation of enterprise architecture complexity. Keywords: Enterprise Architecture; EA patterns; Analysis of Enterprise Architecture; Complexity. 1. Introduction The Enterprise Architecture defines how information and technology will support the business operations and provide benefits for the business. EA is not only a kind of theory to support business and IT alignment, but also a useful and practical methodology. Combining EA and complexity analysis has the advantages of being able to analyze the IT systems in their enterprise wide context. In previous research, managing complexity has been identified as one major challenge in enterprise architecting [29], however IS literature has not mentioned a holistic, i.e. applicable to all dimensions and elements of an EA, approach to quantify complexity in EAs so far[30]. The goal of this paper is to (1) analyze the current state-of- the -art regarding dimensions of complexity and approaches for evaluating EA complexity, (2) identify the components of enterprise architecture based on the information pattern and (3), precise available metrics to calculate the complexity of enterprise architecture using the network theoretic model. The paper is structured as follows: the second section describes the state of the art of our research, the third section details our proposed approach and presents some of our results, the fourth section presents the numeric results of the components complexity of the proposed method and finally, the last section is dedicated to conclude our paper. The case study which is used in this paper is an abbreviated version of a study under development in a private university. This is done to give a more comprehensive presentation of how the method can be used and to demonstrate the efficacy of our approach. 2. State of the art In the following section, we present our literature review related to our research. We define the complexity and its dimensions and the existing methods in the literature which discussed and developed a method of evaluating enterprise architecture. 2.1 Complexity – definition and dimensions According to Davis and LeBlanc [5] the complexity of application architecture is ―number of its components or elements, kind or type of elements and structure of the relationship between elements‖. On the infrastructure architecture level defined complexity as ―The complexity can be defined here as the dramatic increase in the number and heterogeneity of included components, relations, and their dynamic and unexpected interactions in IT solutions‖[32], another definition proposed by [31] covers all aspects of complexity ―The complexity can be defined on the basis of the number and variety of components and interactions plus the rate of change of these‖. From the different definitions cited we can notice that the complexity is a fuzzy term, because different stakeholders have generally different views and conceptions of complexity term, as shows the figure 1 below. From these definitions we will clarify the dimensions of complexity and proposed a global definition which is ―The complexity of architecture is the description of its structure and quantification of the numbers and heterogeneity of components and relations between them over the time‖. The figure 2 shows the four dimensions of the complexity of enterprise architecture, although the number of components IJCSI International Journal of Computer Science Issues, Volume 13, Issue 6, November 2016 ISSN (Print): 1694-0814 | ISSN (Online): 1694-0784 www.IJCSI.org https://doi.org/10.20943/01201606.1524 15 2016 International Journal of Computer Science Issues