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Schedule is Different

Access to new resource related to Earned Schedule added to PMWL



Resource provided by Victor Dantas

11 May 2022 – São Paulo, Brazil – Access to a new resource has been added to the PM World Library (PMWL) related to Earned Schedule and time management. The new resource titled “Schedule is different” is a paper by Walt Lipke published in The Measurable News in 2003.

This article introduces the readers to a distortion that happens commonly in Earned Value Management (EVM): if a project is completed behind schedule, the Schedule Variance (SV) would still be zero. Consequently, the Schedule Performance Index (SPI) should be a unit even in such cases. All this happens because EVM measures schedule performance in units of cost rather than time. This fact can lead those with less expertise in project management techniques to gross misunderstandings.

The author, Walt Lipke, is considered one of the forerunners of the solution to the problem above mentioned. He coined then the concept of “Earned Schedule” (ES): instead of using cost for measuring schedule performance, one would use time. Indicators of ES are very much like their ‘peer’ traditional cost indicators, but bring more useful information over the schedule of a project. The calculation of ES is non-complex and linear and provides project managers with insights as to whether their projects are on the right path of the schedule or behind it.

To access this new resource, go to the Applications and Hot Topics section of the library at, scroll down to Basic Project Management, click on “Scheduling and Time Management”, scroll down to resource. Must be a registered member and logged-in to access. If you are not registered, please consider the 30-Day FREE Trial.

This new resource provided through the PMWL university research internship program; to learn more, click here