Metrics for Evaluating Coupling and Service Granularity in Service Oriented Architecture

Service oriented architecture (SOA) is becoming an increasingly popular architectural style for many organizations due to the promised agility, flexibility benefits. Although the concept of SOA has been described in research and industry literature, there are currently few SOA metrics designed to measure the appropriateness of service granularity and service coupling between services and clients. This paper defines the metrics centered around service design principles concerning loosely-coupled and well-chosen granularity. The metrics are based on information-theoretic principles, and are used to predict the quality of the final software product. The usefulness of the metrics is illustrated through a case study.