This paper describes the systematic integration methodology utilized to assess the subsystem design process and identify integration technologies across different aircraft utility subsystems. The methodology was developed in support of the Air Force Study Contract SUIT (SUbsystem Integration Technology).Traditionally, the design of aircraft utility subsystems has been accomplished individually by each subsystem designer who is responsible for insuring that subsystem interfaces are defined according to a set of accepted industry practices and guidelines. Each subsystem design is optimized with respect to its driving parameters and retains the previously defined interfaces. The task of the airframe or engine integrator is to install these subsystems in the aircraft or the power plant and to control the subsystem interfaces. Therefore, the utility subsystem suite that exists in modern aircraft has not been designed from the ground up in an integrated collaborative manner. Individual subsystems have been designed independently and these individual subsystems are made to work in close proximity with one another almost as if the other subsystems do not exist.As aircraft become more sophisticated and dynamic coupling between the subsystems becomes a significant design issue, it is imperative that the integration of the subsystems be accomplished during the conceptual design of the vehicle to insure that the overall optimization of the airframe, engine and subsystems is accomplished and that all the relevant factors and subsystems couplings are taken into account.The potential benefits from a more collaborative design could be significant and far reaching to the overall aircraft system.The objective of the Subsystem Integration Technology (SUIT) program was to assess the integration possibilities in the design of aircraft utility subsystems, to explore the technology availability to perform the integration and to create a roadmap for the technology development and demonstrations.This paper outlines the methodology developed to assess the subsystem integration potential and provides some of the preliminary results and recommendations for additional studies.