For large software systems, testing phase seems to have profound effect on the overallacceptability and quality of the final product. The success of this activity can be judged by measuringthe testability of the software. A good measure for testability can better manage the testing effort andtime. Different Object Oriented Metrics are used in measurement of object-oriented testability but noneof them is alone sufficient to give an overall reflection of software testability. Thus an integratedmeasure considering the effect of all these measures is required to well define the testability. The papercombines OO software metric values into a single overall value (called Testability Index) that can beused to calculate the testability of a class. The approach uses fuzzy techniques and concepts(fuzzification of crisp metric values, inference and aggregation, defuzzification of fuzzy output). Weinclude empirical data of testing time of 25 different Java classes, which proves that individual metricvalues are not sufficient to arrive at the testability of a class and validates the testability index as agood integrated measure for arriving at the testability of the class.
