The goal of this proposal is to research software engineering techniques, processes, tools, and guidance to determine which would facilitate a software simulation environment that is very modular and adaptable. How to best perform testing on simulators will also be evaluated. As proof of the concept, the chosen software engineering methods would be utilized to design a modular simulation system that would, for the first time, allow researchers the flexibility to develop, modify, and execute control systems and aircraft simulations without extensive re-coding for each new simulation and simultaneously to maintain strict configuration control. This would greatly increase the productivity of aerospace research requiring the use of LaRC software simulators. A report would be generated that would document the lessons learned and successfulness of the software engineering and the verification and validation methods chosen. The results would be applicable to other NASA simulation environments as well as industry.