Vanhoucke, Mario2017-12-022017-12-022013http://hdl.handle.net/20.500.12127/4888Ten years after the introduction of the Earned Schedule concept proposed by Lipke (2003), researchers and practitioners have investigated, validated, criticized and modified this novel concept and successfully used it in research simulation studies, software development and practical project control settings. Only one year later, Lipke (2004) proposed an extension on his Earned Schedule concept to measure the influence of rework due to the lack of scheduling adherence on the earned value. His new concept, known as the p-factor approach, measures the portion of the Earned Value (EV) accrued in congruence with the baseline schedule, which will be used to adapt the current EV to a so-called efective EV (EV(e)) taking the risk of rework into account. Unlike the ES concept, the p-factor approach has up to now stayed in the background, and little adoption by both researchers and practitioners has been detected. The aim of this article is to review this interesting p-factor concept with an artificial project example and to partially illustrate its strengths and weaknesses based on a research study using fictitious and empirical project dataenOperations & Supply Chain ManagementThe Measurable News586145821