Since the mid-1990s, the U.S. Department of Defense has sought ways to improve the acquisition process by applying modeling and simulation (M&S) tools and data in a collaborative fashion involving government customers and industry providers. Originally known as (Distributed) Simulation Based Acquisition, over the past decade, these concepts have evolved under various monikers, including Model Based Systems Engineering, originated by the International Council on Systems Engineering, and Model Based Engineering, a term that has been used by the Office of the Secretary of Defense (OSD) and the National Defense Industrial Association (NDIA). OSD has recently introduced a concept for a (Digital) System Model that evolves throughout the acquisition lifecycle, and the U.S. Air Force has coined the terms Digital Thread and Digital Twin that complement the OSD concept. As these concepts have evolved, the M&S Committee of NDIA's Systems Engineering Division has performed two technical studies that help to describe the application of M&S tools/data during the acquisition lifecycle. This paper provides a summary of the results of these two studies. The first study, the identification of M&S capabilities across all acquisition lifecycle phases, resulted in the development of a multi-spreadsheet workbook that links activities in each lifecycle phase with M&S capabilities that support performing those activities, along with example tools that can be used to implement those M&S capabilities. The second study, the identification of essential elements of the system model, instantiates the high-level system model concept by defining the data/information needed for its implementation, linked to the acquisition activities and M&S capabilities identified during the first study. Finally, the paper presents a potential way ahead for integrating these concepts and studies to formulate a high-level approach for an overarching collaborative M&S environment centered on the system model concept.