(IJCNS) International Journal of Computer and Network Security, Vol. 2, No. 3, March 2010 20 An Integrated Approach for Legacy Information System Evolution Dr. Shahanawaj Ahamad 1 1 Department of Computer Science College of Arts & Science in Wadi Al-Dawasir, King Saud University Wadi Al-Dawasir-11991 Kingdom of Saudi Arabia. sa_sum@yahoo.com Abstract: Future legacy evolution has always been a great challenge because of continuous changes in business operation influenced by requirements changes, production of large commercial benefits, information and communication technologies development. Usually legacies are not been made to accommodate these fast changing advancements, this is one of the basic challenge of legacy evolution and renovation also requires forward and backward procedures and specific knowledge generation for renovators. Web enabling legacy and COBOL based applications interaction with e-commerce based application is potentially hard to maintain and loss huge amount of organizational economical assets, this paper proposes the solutions procedures in this evolutionary direction so that on demand legacy evolution can be performed through adaptive maintenances. Keywords: Legacy Systems; Software Evolution; Legacy Modules; Legacy Code; Legacy Restructuring. 1. Introduction This paper presents a closer look at software renovation and explains how legacy software evolutions take place for future change. It is based on the view that an organization's software systems provide valuable functionality that has been proven in practice. As such, it should be reused whenever possible. At the same time, the packaging of this business functionality is usually far from optimal as they are often based on old languages, database systems, and transaction monitors, monolithic in design, and non maintainable as a result of repeated modification without supporting documents. As a consequence, legacy systems are very hard to change. A software system can be effectively evolved with following procedures: • Modularization • Restructuring • Analysis • Reformation • Transformation. Procedures proposed are explained in the following sections. 2. Related Work This work is motivated by migration approach suggested in [11] that explains why a module based migration approach can be implemented for software maintenance, paper also suggested in this direction but with legacy technical aspects and implantation procedures. 3. Modularization Following fig. 1 depicts how the legacy source is divided in to interacting modules. Figure 1: Dividing legacy source in modules Following are some identified issues associated with this procedure: • Availability of legacy sources. • Language used to develop legacy source. • Complexity of source understanding and comprehension. • Status of documentation and complexity in re- documentation. • Implementation of the tools for analysis and results description. • Check feasibility of division of modules. If division of source in modules is feasible and above mentioned issues are resolved then undertake next sequence of procedural approach. 4. Restructuring Intercommunication of the modules using organized of architecture is to replace the internal structure of the legacy