Comparison of Earned Schedule to EVMS Schedule and Metrics

摘要

This paper summarizes an analysis of a comparison between standard EVMS metrics and an Earned Schedule (ES) approach, to see if use of ES would provide more meaningful forecasting data versus conventional EVMS analyses. Seven facilities were initially selected for this analysis, which are part of a large waste treatment facility complex being built by the U.S. Government in the Pacific Northwest. These facilities were under-going engineering, procurement, and construction (EPC) during calendar years 2002 to 2012. Initial analysis indicates that the ES metrics for the EPC portion of the facilities - which range in price from about $4 to $19 million - appear to provide a meaningful indication of the schedule variance in terms of months, especially towards the end of a project. It was found, though, that sometimes the ES metric can overstate the actual progress. An anticipated direct comparison to the actual corresponding schedules was not able to be made, so a review of some time-based Independent Estimate at Completion metrics was conducted.