The purpose of this study is to present guidelines that can be followed when introducing Service-oriented architecture through the use of Web services. This guideline will be especially useful for organizations migrating from their existing legacy systems where the need also arises to consider the financial implications of such an investment whether it is worthwhile or not. The proposed implementation guide aims at increasing the chances of IT departments in organizations to ensure a successful integration of SOA into their system and secure strong financial commitment from the executive management. Service oriented architecture technology is a new concept, a new way of looking at a system which has emerged in the IT world and can be implemented by several methods of which Web services is one platform. Since it is a developing technology, organizations need to be cautious on how to implement this technology to obtain maximum benefits. Though a well-designed, service-oriented environment can simplify and streamline many aspects of information technology and business, achieving this state is not an easy task. Traditionally, management finds it very difficult to justify the considerable cost of modernization, let alone shouldering the risk without achieving some benefits in terms of business value. The study identifies some common best practices of implementing SOA and the use of Web services, steps to successfully migrate from legacy systems to componentized or service enabled systems. The study also identified how to present financial return on investment and business benefits to the management in order to secure the necessary funds. This master thesis is based on academic literature study, professional research journals and publications, interview with business organizations currently working on service oriented architecture. I present guidelines that can be of assistance to migrate from legacy systems to service-oriented architecture based on the analysis from comparing information sources mentioned above.