Abstract: The quality of any object oriented design is critical because it has a great influence on overall quality of finally delivered software product. Testability quantification early in the software development process is a criterion of crucial important to software development team. Testability has always been an indefinable concept its correct measurement, quantification or evaluation is a difficult task because of its potential factors. Testability analysis of object oriented software at an initial stage of software development process has been identified as a key factor for high quality product. A best suited object oriented design (OOD) properties and its associated metrics are helpful if applied in the early stage of development process .This paper describes an improved testability quantification framework using the identified set of potential factors, OOD properties and OOD metrics for software products at early phase, exclusively at design time. The proposed framework relates OOD properties to high level quality attributes/constructs using appropriate information to develop quality product and it may used to benchmark software products according to their key attribute. The objective of this research work to encourage researchers and developers to provide a framework to access and quantify software testability at early stage of development life cycle.

Keywords: Testability, Object Oriented Design, Testability Framework, Object Oriented Software, Software Quality Model, Software Testing, Effort Estimation