International Journal of Computer Applications (0975 – 8887) Volume 61– No.13, January 2013 29 A Meta-Model for Migrating a Legacy Information System based on Procedural Software Architecture towards Service Oriented Architecture Slim Jendoubi National School of Informatics Sciences (ENSI) University of Manouba, 2010 Tunisia Jamil Dimassi National School of Informatics Sciences (ENSI) University of Manouba, 2010 Tunisia Henda Ben Ghezala National School of Informatics Sciences (ENSI) University of Manouba, 2010 Tunisia ABSTRACT During several years, the computing environments became more complex and more heterogeneous because of the diversity of customer’s needs and of the technological evolutions. The agreement between applications and different technologies became a critical activity. So, to face this problem of interoperability, companies often resort to the solutions of enterprise application integration (EAI). In what concerns us, we consider the EAI as being at the same time the strategy and the process that companies allow to reach a solution of optimal integration of the various heterogeneous, autonomous and distributed applications. In this context, this paper consists on presenting a generic meta-model for integrating legacy applications with service oriented architecture. Indeed, to resolve the problem of interoperability between applications, this meta-model aims at capitalizing on procedural legacy applications and their integration into modern environments. Keywords procedural information system; legacy application; interoperability; software architecture; management process; SOA. 1. INTRODUCTION During the last three decades, a significant number of software based on procedural paradigm was developed. Nowadays, these developments constitute a big part of the application heritage of companies. Indeed, this paradigm is allowed to release itself from the code machine and to strengthen a separation between the data representations and their processing. However, the development of complex systems using this paradigm was generated chaotic structures for information system. So, the maintenance of the procedural systems is a complex and an expensive task and the re-use of the code is often compromised. Consequently, the modernization of these systems became indispensable. To satisfy increasing needs to integrate applications, various tools are proposed. However, most of them present several limits [11]. On the one hand, these solutions miss abstraction and strategic methodology; they are developed without strategic vision and prioritize technological objectives. On the other hand, these solutions do not considerate the software architecture of the applications to be integrated. Moreover, none of these solutions answers strategically the need of integrating procedural legacy applications with service oriented architecture. The interest to worry about these two paradigms, legacy and service oriented, comes because the first one is very former. Besides, the procedural legacy applications constitute a big part of the application heritage of most of the companies and envisage several difficulties for their integration with the new technologies, whereas the second is recent and fashionable. Furthermore, the service oriented architecture appears as the best approach allowing a flexible integration of the autonomous, distributed and heterogeneous applications within the company. This paper is organized as follow: The second section gives a brief description of software architectures based on the procedural paradigm. The third section presents a meta-model that we propose for integrating procedural legacy applications with service oriented architecture. 2. THE LEGACY SYSTEMS 2.1 Definition A legacy system is defined as " Any information system inherited from the last years, in practice from 1970 till 1995, generally developed ‘in-house’ to support the important functions, essential in the functioning of companies " [7]. Concerning us, legacy systems are information systems potentially impossible to maintain, whose total ownership cost is very high and for whom the skills are lacking. These systems are not rather flexible to support the evolution of the technologies and the business enterprise needs. However, these legacy systems represent the core of several information systems of companies, which depend on their specifications and their daily activities. 2.2 Problems related to legacy systems The presence of legacy systems within companies creates certain problems, the main clauses of which are [12]: - The technological disuse: difficulties to develop technical environments which are more or less supported by their suppliers. - The rarity of the skills: given the competent staff on this type of applications is more and more rare (retirements, promotions, progress of career), the maintenance and the evolution of these systems became complex, even impossible. - A significant loss of consciousness and a more and more anarchy development due to the age of the