1. A process of designing a composite application system, the method comprising: defining a plurality of case scenarios performed by a composite application system in a composite application system design; integrating the plurality of case scenarios with a plurality of execution tools; and specifying an underlying infrastructure for the system design to embody the plurality of execution tools to select a plurality of components whose combination meets a plurality of application requirements, wherein specifying the underlying infrastructure comprises: i) estimating a performance of the underlying infrastructure according to the composite application system design; ii) evaluating a feasibility of the composite application system design; and iii) identifying potential flaws of a feasible composite application system design, wherein the process is performed in an integrated software application executed in a computing system.