The main goal of model testing is to find system errors at the systems analysis and design stage and thereby reduce the cost of software testing and enhance the efficiency of system development. Prior researches proposed an Integrated Method which utilizes the artifacts from the Platform Independent Model (PIM) to construct the test path and constrained class tuples (CCT). These two can then be integrated to construct an Integrated Testing Model (ITM) for determining the test data and test cases for Model-Based Testing. This study develops a methodology which extracting the information from the Sequence Diagram and Class Diagram from the PIM to construct an ITM. The research methodology is articulated using the design science research methodology. A prototype embedded methodology has been developed. A usability evaluation is performed on the prototype to demonstrate its usability in terms of the factors, efficiency and effectiveness. With this methodology, the test paths, CCT and ITM can be generated automatically; thereby reducing the costs and increasing the efficiency of Model-Based Testing.