A metrics suite and fuzzy model for measuring coupling in Service Oriented Architecture

The paper proposes a suite of metrics for measuring coupling in service oriented architecture. The principle characteristic of Service Oriented Architecture is loose coupling. Coupling means that the existence and the extent of dependency between modules, components, or services consumers and providers. The coupling is an important aspect in the evaluation of reusability of components or services. In this paper we propose a suite of metrics for measuring the degree of coupling in services at the design phase. The dependencies between services cause coupling. Many coupling metrics have already been proposed but it is recognised that the dependencies they considered for measuring coupling are insufficient. This paper takes five kinds of dependencies viz. direct dependency, indirect dependency, IO dependency, and State dependency and Delayed Message dependency to evaluate the degree of coupling in a service. The paper also proposes a fuzzy logic model to measure the degree of coupling due to these dependencies.