The purpose of this study was to investigate the stability of the cost performance index (CPI) for environmental remediation projects as the topic is not addressed in the literature. CPI is defined as the earned value of work performed divided by the actual cost of the work, and CPI stability represents the point in time in a project after which the CPI varies by less than 20 percent (measured in different ways).
Journal of Defense Analytics and Logistics
Clayson, Denis S.; White, Edward D.; and Thal, Albert E. Jr., "Cost Performance Index Stability: Insights from Environmental Remediation Projects" (2018). Faculty Publications. 138.