Future aircraft systems are projected to have order of magnitude greater power and thermal demands, along with tighter constraints on the performance of the power and thermal management subsystems. This trend has led to the need for a fully integrated design process where power and thermal systems, and their interactions, are considered simultaneously. To support this new design paradigm, a general framework for codifying and checking specifications and requirements is presented. This framework is domain independent and can be used to translate requirement language into a structured definition that can be quickly queried and applied to simulation and measurement data. It is constructed by generalizing a previously developed power quality analysis framework. The application of this framework is demonstrated through the translation of thermal specifications for airborne electrical equipment, into the SPecification And Requirement Evaluation (SPARE) Tool. The SPARE Tool is a MATLAB toolbox that automates both the thermal and power quality analysis of simulation and experimental data based on the techniques discussed in this paper. The combination of both thermal and power quality analysis into one tool, demonstrates how a single program can be used to analyze requirements across both power and thermal systems. A sample inverter design problem is used to illustrate how the SPARE Tool can be used to analyze thermal requirements and identify potential design compromises between the electrical and thermal domains. This example shows the value of multi-domain analysis programs, like the SPARE Tool. Use of such tools will enhance collaboration, speed up design iterations, and aid engineers and researchers in meeting the design challenges of future aircraft systems.