This thesis discusses the ability to maintain a consistent design, simulation, and test verification environment by use of the Process Model Graph (PMG) throughout the development process. This ability extends the functionality of the PMG to include the visualization of simulation results and the verification of test paths within the simulation. These ideas have been implemented within a development tool called the Modeler's Assistant. The integration of the test generation environment into the tool is discussed. The design methodology used in creating the simulation environment is also discussed. Other enhancements to increase the abilities of the tool and improve its usefulness to behavioral test generation and verification are also discussed. Many examples of the new extentions to the tool are presented.