Analysis of Time-Phased Estimates Accuracy, Budget Profile and Under-Spending in Defense Acquisition Programs

As fiscal resources become more limited due to the expanding range of mission needs, accurate cost estimating and budgeting have become more important than ever before. Accurate cost estimates allow the Department of Defense (DoD) to budget with confidence and to effectively communicate its needs to Congress. This research looks to analyze estimates from Air Force’s programs using Milestone B and Initial Operational Capability as the analysis window. Initial analysis of the linear interpolation of the percent budget change indicates that there is underspending in the earlier stages of acquisition programs’ development cycle. Additionally, looking at the cumulative budget change in relation to the cumulative percent schedule, with the two outlier programs B2-RMP and SDB II accounted for, significant budget changes tend to occur near the end of acquisition programs’ life cycle, particularly around the 70% - 80% schedule mark and on. Then, an analysis of the S-curve suggests that, overall, acquisition programs tend to reach 60% of total program budget around the 50% schedule mark. Finally, the years-prior analysis indicates that, overall, time-phased estimates tend to be more accurate when performed within two years of the budget year