This paper presents a surrogate model approach to advance fundamental research on understanding impacts of engineering decision-making on complex system performance and system development cycle times. The approach is motivated by digital transformation and advancement of the digital engineering strategy by the U.S. Department of Defense as part of acquisition modernization. The digital engineering strategy focuses on five goals as a means to reduce acquisition cycle times and increase capability deployment to the warfighter, but we lack the theory to understand the impact of the digital transformation on engineering processes, decision- making and the solution performance. The surrogate model approach discussed herein could provide a methodology for studying the impact of digital engineering on solution performance and lifecycle development time on a wide class of design problems with tunable complexity.