State of the Practice in Service Identification for SOA Migration in Industry

The migration of legacy software systems to Service Oriented Architectures (SOA) has become a mainstream trend for modernizing enterprise software systems. A key step in SOA migration is the identification of services in the target application, but it is a challenging one to the extent that the potential services (1) embody reusable functionalities, (2) can be developed in a cost-effective manner, and (3) should be easy to maintain. In this paper, we report on state of the practice of SOA migration in industry. We surveyed 45 practitioners of legacy-to-SOA migration to understand how migration, in general, and service identification (SI), in particular are done. Key findings include: (1) reducing maintenance costs is a key driver in SOA migration, (2) domain knowledge and source code of legacy applications are most often used respectively in a hybrid top-down and bottom-up approach for SI, (3) industrial SI methods focus on domain services–as opposed to technical services, (4) there is very little automation of SI in industry, and (5) RESTful services and microservices are the most frequent target architectures. We conclude with a set of recommendations and best practices.