Houston — NASA has met with limited success in efforts to embrace an earned value management (EVM) system capable of predicting cost overruns and schedule slips on major spaceflight projects such as the troubled James Webb Space Telescope, according to a Government Accountability Office audit prepared for House and Senate oversight panels.

The agency’s portfolio included 21 major projects projected to cost a total of $19.4 billion at completion during the GAO’s yearlong audit period that concluded in August 2011.

Congressional auditors examined 10 of the projects, with a combined value of $14 billion, and found just three generating reliable EVM data: the Mars Atmospheric and Volatile Evolution Mission (Maven), the Orbiting Carbon Observatory 2 and the Radiation Belt Storm Probes.

“If done correctly, EVM data can provide an objective means for measuring project status and forecasting potential cost overruns and schedule slippage so that timely action can be taken to minimize their impact,” GAO noted in its 104-page report. “However, NASA is not making full use of a key tool that could help it address the cost and schedule issues that have kept NASA acquisition management on GAO’s high-risk list for more than 20 years.”

The auditors cited cultural resistance, a lack of resources, inadequate training and differing performance metrics applied by the agency’s contractors, academic and other nongovernmental partners as among the major obstacles to timely EVM implementation.

In a response prepared by Michael Ryschkewitsch, NASA’s chief engineer, the agency concurred with the need for a skills assessment and a change management plan, but cited resource constraints in addressing the data reliability/oversight issue.

“NASA agrees with GAO that EVM is one of the many valuable tools used to assess and manage performance and values the GAO’s feedback in this area,” Ryschkewitsch said.