A Metrics Suite for Evaluating Flexibility and Complexity in Service Oriented Architectures

Service Oriented Architecture (SOA) is emerging to be the predominant architectural style of choice for many organizations due to the promised agility, flexibility and resilience benefits. However, there are currently few SOA metrics designed to evaluate complexity, effort estimates and health status of SOA solutions. This paper therefore proposes a SOA metrics framework which includes both service level and SOA-wide metrics to measure design and runtime qualities of a SOA solution. The SOA-wide metrics predict the overall complexity, agility and health status of SOA solutions, while service level metrics focus on the fundamental building blocks of SOA, i.e. services. The combined views deliver a compelling suite of SOA metrics that would benefit organizations as they consider adopting SOA. These metrics, which are based on observations of many SOA engagements, are illustrated through a case study that describes a recent ongoing project at IBM where SOA was utilized to build the solution assets.