Measuring performance of an ongoing project is a difficult task. The best method to understand performance, is to primarily determine the KPI's, which in turn will give us a clear idea on which parameters we want to measure the performance of a project. Proper measurement can help us to understand the area where a project is lacking and why. It also helps us to manage expectations of stakeholders and issue warnings against any upcoming problems which might arise in future. Please go through the link for more details: http://www.projecttimes.com/george-pitagorsky/measuring-in-progress-project-performance.html