Excerpt from the Proceedings of the Nineteenth Annual Acquisition Research SymposiumThis paper is part of a research agenda outlined in Franck et al. (2016) directed toward improving the realism of defense acquisition schedules. Defense acquisition schedules have long been a difficult problem. In this particular effort, we consider primarily the case of the 737MAX, which has been a fortuitous example of the risks of scheduling-by-fiat. We analyze the 737MAX misadventure using systems dynamics and root cause analysis methods. A fundamental question for defense acquisition schedule estimating is the extent to which schedule drivers vary (or don’t) across various defense acquisition programs. If the programs are, in fact, idiosyncratic in nature, then we have prospects of explaining observed schedules (with program-specific explanatory variables). However, to the extent that common themes drive schedules across whole classes of programs, we have better prospects of predicting expected schedule length. This paper aims to (a) present a useful perspective of this question and (b) offer suggestions for the way forward.Approved for public release; distribution is unlimited