Application model development and validation is a complex process that relies extensively on human capabilities for analysis, judgment, and synthesis of large amounts of diverse information. This process requires the support from automation to produce a technically complete AP. The model validation process and the STEP development methods place unique requirements on the software that will be needed to support the effective testing of STEP. The National PDES Testbed at the National Institute of Standards and Technology has undertaken a software project to support this process. The current direction of this project has been formulated from our initial experiences in exercising this process and with software automation for the model validation testing. In addition, this paper introduces the potential contribution that application model validation and validation tools could make to the conformance testing of AP implementations.