ANALYZING STABILITY OF ESTIMATES AT COMPLETION FOR LONG DURATION DEVELOPMENT EFFORTS.

Defense program managers utilize Earned Value Management (EVM) methodologies to measure, report, and predict the cost and schedule performance of their programs. Previous research conducted by Christensen (1996) and Kim et al. (2019) has shown varied results in the stability of EVM Estimates at Completion (EACs). Stability is defined as a 10% or less deviation from the final EAC at a specified percent completion point of the program. The Christensen (1996) and Kim et al. (2019) studies also noted that program-specific factors, such as phase, can impact the accuracy of EVM metrics. This study builds upon those works by assessing EAC stability specifically for defense programs characterized by one such factor: long duration development efforts. In addition, EAC stability using Earned Schedule (ES) metrics are also assessed and statistically compared to the EVM results. The authors found stability at around 70% completion. This result is later in the project than previous research wherein the researchers did not consider project duration in their findings. Additionally, no significant differences in EAC stability were found with ES metrics in comparison to the EVM results. Therefore, program managers are cautioned to consider the length of duration when estimating cost at completion up to and slightly beyond the 70% completion point. [ABSTRACT FROM AUTHOR]