An Architectural Efficiency based methodology for assessing the relative merit of synchronous vs. asynchronous service invocations

There are very few architectural issues that invite as much religious ardor as the question of whether to connect to a remote service asynchronously or synchronously. To arguments of architectural decoupling in favor of the asynchronous option some architects and developers will continue to argue in favor of the simplicity of the synchronous option. This paper proposes to introduce new insights to such debate through an Architectural Efficiency analysis, an approach that will turn out to reveal major differentiators between the two alternatives, thus also validating the methodology to this particular domain of analysis.