Data Engineering, Process Engineering, and Constraint Engineering for Management of M&S Interoperation enabling Embedded Decision Support Andreas Tolk 1 , Saikou Y. Diallo 2 , Robert D. King 2 , Charles D. Turnitsa 2 1 Frank Batten College for Engineering and Technology, Old Dominion University, 5115 Hampton Boulevard, Norfolk, Virginia 23529, United States of America 2 Virginia Modeling Analysis & Simulation Center, Old Dominion University, 1030 University Blvd Suffolk, Virginia 23435, United States of America Email corresponding author: atolk@odu.edu ABSTRACT The use of Modeling & Simulation (M&S) services in operational systems for decision support is a do- main of high interest. Developments in web services and service-oriented architectures build a solid foundation for technical interoperation. This paper addresses the need for data engineering, process en- gineering, and constraints engineering to ensure that model-based applications are not only technically integrated, but that the implementation is interoperable and the concepts are composable. It shows the need to provide annotation enabling identifying potential candidates, selecting the best candidates from this pool, composing the candidates into a coherent and consistent solution, and orchestrating their ex- ecution embedded into the operational environment of the decision maker. If this is not done, the deci- sion maker will receive bad advice, as the supporting systems are not conceptually aligned.