The Air Force has an initiative entitled, Subsystem Integration Technology (SUIT) to develop and demonstrate integration technology as applied to the traditional aircraft utility subsystems. Utility subsystems perform functions such as auxiliary power generation, environmental control, and fuel management. Commonly these different subsystems are developed independently and then interfaced when building a particular flight vehicle. The SUIT program considers all functions accomplished by the traditional utility subsystems to be responsibilities of a single entity called a utility suite. This suite is designed with overall vehicle level performance objectives rather than trying to maximize the performance of individual functions and is not bound to maintaining the traditional allocation of functions among the hardware labeled as fuel management, environmental control, or secondary power. The SUIT program has the objective of developing and demonstrating design data and assessment capability for a truly integrated subsystem suite. Novel concepts for a utility suite have emerged from recently completed concept studies conducted by several contractor teams. These concept studies showed that significant flight vehicle performance benefits appear to be possible via the utility suite approach as a result of the use of common or shared hardware and fluids to perform required functions, use of waste energy, and better overall energy-management. The utility suite approach reduces weight by having less standby hardware, reduces the acquisition and support cost via hardware commonality, provides for graceful degradation, and better energy management. These concept studies also showed that there is no one concept for structuring a utility suite that maximimizes all flight level performance parameters. This means that the integration design and allocation process of utility functions within the utility suite is a design process in and of itself.