Technology Readiness Level, Schedule Risk, and Slippage in Spacecraft Design

Level of the system/payload under development as a principal culprit driving schedule risk and slippage. In this paper, based on data from past space programs, we analyze the relationship between technology uncertainty and schedule risk in the acquisition of space systems and propose an analytical framework to identify appropriate schedule margins for mitigating the risk of schedule slippage. We also introduce the Technology Readiness Level schedule-risk curves to help program managers make risk-informed decisions regarding the appropriate schedule margins for a given program or the appropriate Technology Readiness Level to consider if the program’s schedule were to be exogenously and rigidly constrained. Based on our findings, we recommend that the industry adopt and develop schedule-risk curves (instead of single-schedule point estimates), that these schedule-risk curves be made available to policy- and decision-makers in acquisition programs, and that adequate schedule margins be defined according to an agreed-upon and acceptable schedule-risk level.