Arnold Engineering Development Center (AEDC) is currently improving its test facilities as part of its Test Operations Modernization & Integration Project (TOMIP). The challenge is to apply control system improvements, achieve control room consolidation, and provide operator training for complex test facilities without negatively impacting ongoing test projects. The TOMIP approach has been to target specific subsystems among all the AEDC test cells, rather than focusing on all the subsystems of a specific set of test cells. This makes it possible to minimize downtime and maximize cost savings. For each targeted subsystem, requirements are identified and hardware and software solutions are designed. These solutions are then validated through the use of models and simulations in a development/training area using identical hardware and software. Upon completion of this validation, the hardware is installed in the field and connected to the existing hardware for a complete checkout of the system. This paper discusses the creation of this development area, its communication architecture, and the real-time model and simulation constructed for this project. Furthermore, the checkout procedure followed, and the application of the system to the coding and testing of new programmable logic controllers (PLCs) for the J1 and J2 turbine engine test facilities will be discussed.