Understanding project management performance using a comparative overrun measure

•Project managers need better ways to diagnose project management issues when projects fail to meet initial estimations.•Performance management systems should imbed measures comparing current and past similar project performance for diagnosis.•Performance management literature has not used outside view-based measures to learn about project management performance.•Situating focal project performance in the context of past project performance helps evaluate continuous improvement.•Comparative measures show how project management performance has progressed and support learning from past projects. Project managers need support to diagnose project management performance problems. Diagnosis happens when managers learn about prior project management performance by using outside view information about past projects to situate focal projects within the context of past project management performance. No prior research has incorporated outside view information into performance measures. Hence, we propose a comparative performance measure that compares overrun of a focal project to overrun of past similar projects to promote an understanding of trends across projects. Traditional overrun measures that only compare performance to initial estimates fail to encourage learning from past performance. Our comparative measure can be used to evaluate how well lessons have been leveraged, addressing a lack of existing quantitative measures for learning from previous projects. Project managers need encouragement to use new comparative project performance measures, so they should be embedded in performance management systems with incentives for continuous improvement.