TRACKING COST AND SCHEDULE GROWTH OF UNMANNED SPACECRAFT: LESSONS LEARNED FROM NASA’S CADRE DATABASE

Paper number

IAC-09.D1.5.5

Author

Mr. Gregory Dubos, Georgia Institute of Technology, United States

Coauthor

Mr. Alexander MacDonald, NASA - Ames Research Center, United States

Year

2009

Abstract

Predicting and controlling cost and schedules of space missions is a perennial challenge in space programs around the world. While general hypotheses concerning reasons for cost and
schedule growth have been formulated and single case analyses have been conducted, very few studies
have approached this problem from a statistical perspective. The main reason for the scarcity of detailed
studies concerning space systems is the difficulty in obtaining cost and schedule data for a large number
of missions in a systematic and consistent manner. Partly in response to this need, NASA initiated the
Cost Analysis Data Requirement (CADRe) studies, to collect and record the cost and schedule history of
NASA missions.

This work uses CADRe data to investigate what lessons can be learned regarding cost and
schedule growth of NASA’s space systems. First, we identify trends in engineering and programmatic cost
growth by considering their estimates at different milestones of the development of the space systems in
the database. Second, we explore the reasons for schedule growth, by looking at the difference between
the actual post-launch schedule and the estimated schedule at various mission milestones. We then
discuss the possible correlation between the derived scheduled and cost estimates and various design
parameters, such as mass, nominal power, and design lifetime. We find a number of interesting phenomena
including: an inverse correlation between schedule growth and the number of instruments on a spacecraft;
evidence for “rush to failure” behavior in the detailed design phase; and a trend in “soft” program elements (e.g.
project management and software) that sees cost estimates reduced going from PDR to CDR followed by a strong
increase from CDR to launch. We also identify the extent to which cost and schedule growth are coupled
phenomena in our data sample. Finally, we make recommendations on how to record cost and schedule
information for the CADRe database more consistently based on our experience in collecting the data
used for this study.

Abstract document

IAC-09.D1.5.5.pdf

Manuscript document

IAC-09.D1.5.5.pdf (🔒 authorized access only).

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