1. A method for estimating a quality measure of a composite application, the method comprising: receiving a set of sequence diagrams describing interactions between pairs of components in a composite application, each sequence diagram describing a functional use case of the composite application; receiving a plurality of component quality metrics, wherein each of the plurality of component quality metrics is associated with a component of the composite application; calculating a quality estimation for each use case of the composite application by calculating an average of products of the quality metrics for each interacting pair of components in the associated sequence diagram; calculating a quality measure of the composite application by summing the quality estimation for each use case multiplied by a weight value, wherein the weight value indicates an importance of the corresponding use case; and outputting the quality measure of the composite application.