Schedule Performance Impact from Rework



By Walt Lipke

Oklahoma, USA




The concept of schedule adherence (SA) was introduced several years ago, as a consequence of Earned Schedule. Applying SA in the analysis of project performance yielded task level information; tasks are identified that may have performance restricted by impediments or process constraints, and other tasks that may experience rework in the future. Presently, those applying SA in their management process have focused on the cost impact of rework. This paper takes the next step, providing methods for understanding the impact rework has on schedule performance.


About fifteen years ago, a year after the introduction of Earned Schedule (ES) [Lipke, 2003], the concept of schedule adherence was published [Lipke, 2004]. Schedule adherence extended ES to project management methods for identifying tasks likely to be performance impeded or constrained and those having a potential of rework. As well, it provided methods for computing the portion of earned value (EV) that moves the project toward completion, termed “effective earned value.” Effective EV allowed for computing an effective ES. These effective values could then be employed in the calculation of the variances, indexes, and forecasts attributed to the methods from Earned Value Management (EVM) and ES[1]; thereby providing a pessimistic, but truer view of project performance.

In 2011, the approach for forecasting the total cost of rework caused by SA was developed [Lipke, 2011]. Having the ability to compute the cost impact of rework, in turn, gave project managers reason to increase attention to managing schedule performance and improving planning.

Although facility has been available for calculating the schedule performance impacts of rework, it hasn’t been fully recognized, and certainly not utilized. The application of SA from its introduction several years ago, primarily, has focused on the impact to project cost. This article provides a brief review of ES and SA, and then presents methods for computing the impact of rework on schedule performance. 


Earned Schedule

Earned Schedule is dependent upon EVM; the ES measure is derived from the accrued earned value (EV) and the performance measurement baseline (PMB) [Lipke, 2003]. As shown in figure 1, “…the idea is to determine the time at which the EV accrued should have occurred.” The time duration from project start to the point on the PMB where the planned value (PV) equals the EV accrued is the earned portion of the planned duration (PD), i.e. ES. The calculation method for determining the value of ES is explained, in detail, in the Earned Schedule book [Lipke, 2009].


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How to cite this paper: Lipke, W. (2020). Schedule Performance Impact from Rework; PM World Journal, Vol. IX, Issue I, January.  Available online at https://pmworldlibrary.net/wp-content/uploads/2020/01/pmwj89-Jan2020-Lipke-schedule-performance-impact-from-rework.pdf



About the Author


Walt Lipke

Oklahoma City, USA




Walt Lipke retired in 2005 as deputy chief of the Software Division at Tinker Air Force Base, where he led the organization to the 1999 SEI/IEEE award for Software Process Achievement. He is the creator of the Earned Schedule technique, which extracts schedule information from earned value data.

Credentials & Honors:

  • Master of Science degree in Physics
  • Licensed Professional Engineer
  • Graduate of DOD Program Management Course
  • Physics honor society – Sigma Pi Sigma (SPS)
  • Academic honors – Phi Kappa Phi (FKF)
  • PMI Metrics SIG Scholar Award (2007)
  • PMI Eric Jenett Award (2007)
  • Who’s Who in the World (2010)
  • EVM Europe Award (2013)
  • CPM Driessnack Award (2014)
  • Australian Project Governance and Control Symposium established the annual Walt Lipke Project Governance and Control Excellence Award (2017)
  • Albert Nelson Marquis Lifetime Achievement Award (2018)

To view other works by Walt Lipke, visit his author showcase in the PM World Library at https://pmworldlibrary.net/authors/walt-lipke/


[1] Reference [PMI, 2011] for EVM and ES terminology definitions and formulas for variances, indexes, and forecasts.