Technology Readiness Level, Schedule Risk and Slippage in Spacecraft Design: Data Analysis and Modeling

Schedule slippage plagues the space industry, and is antinomic with the recent emphasis on spaceresponsiveness. The Government Accountability Office has repeatedly noted the difficultiesencountered by the Department of Defense in keeping its acquisition of space systems on schedule,and identified the low Technology Readiness Level (TRL) of the system/payload under developmentas a principal culprit driving schedule risk and slippage.In this paper, we analyze based on data from past space programs the relationship betweentechnology uncertainty and schedule risk in the acquisition of space systems, and propose ananalytical framework to identify appropriate schedule margins for mitigating the risk of scheduleslippage. We also introduce the TRL-schedule-risk curves to help program managers make riskinformeddecisions regarding the appropriate schedule margins for a given program, or theappropriate TRL to consider should the program’s schedule be exogenously and rigidly constrained.We recommend based on our findings, that the industry adopts and develops schedule risk curves(instead of single schedule point estimates), 2) that these schedule risk curves be made available topolicy- and decision-makers in acquisition programs; and 3) that adequate schedule margins bedefined according to an agreed upon and acceptable schedule risk level.