Abstract : The Department of Defense (DoD) s Science & Technology (ST most notably is the USMC funded Framework for Assessing Cost and Technology (FACT). In parallel, the U.S. Army Research Laboratory (ARL) has been pursuing the Executable Architecture Systems Engineering (EASE) research project, which links analytical, experimental and training objectives with the technical complexity of modeling and simulation in an easy to use, scalable tool. This document describes an effort to develop a formal Application Programming Interface (API) between FACT and EASE, creating the ability to develop system concepts and assess Measures of Performance (in FACT), and then send those system concepts to a campaign simulation to assess Measures of Effectiveness (through EASE), and then back to FACT for a high-level tradestudy. A strategic objective of this work is to lay the foundation for an ERS Tradespace software architecture.