The intent of this article is to explore a mathematically sound method to graphically monitor schedule performance index (SPI) such that it enables the project manager to take objective data based decisions regarding the progress of the project schedule. The article aims to leverage the theory and application of control charts, specifically the U chart and Laney U chart and test its applicability to earned value management by trending schedule performance index on a time series chart. Off the shelf software, MinitabTM was used to generate the control charts based on earned value and planned value. While this paper proves that the Laney U chart, with correct interpretation, acts as an effective trigger-based tool for schedule risk management, it also generates further avenues for research into similar use of control charts for cost performance and other quality indices.