A method engineering based legacy to SOA migration method

Legacy systems are vitally important for the continuation of business in an enterprise as they support complex core business processes. However, legacy systems have several well-known disadvantages such as being inflexible and hard to maintain, so momentum is growing to evolve those systems into new technology environments. Recently, service-oriented architecture has emerged as a promising architectural style that enables existing legacy systems to expose their functionality as services, without making significant changes to the legacy systems themselves. A significant number of the legacy to service migration approaches address the technical perspective (i.e., supporting technology) to expose the legacy code as services. The other approaches focus on determining the feasibility of the migration that includes economical and technical feasibility, based on the characteristics of existing legacy system and the requirements of the target SOA system. In this paper, a legacy to SOA migration method that does not single out the migration feasibility and technical perspectives, but combines these two perspectives of migration, is proposed. Method engineering is used to develop the migration method by reusing method fragments from existing service-oriented development methods. Then, concept slicing is used to develop the service by extracting the relevant parts of the legacy code. The method is evaluated and enhanced by interviewing experts and further validated with two case studies. The method is found to be appropriate and effective in extracting services from legacy code with the aim of reusing these services in new configurations.