Change, a major cause of litigation, is inevitable and necessary to optimize a construction project. However, using litigation as the ultimate resolution is the last alternative for construction disputes, taking a huge amount of costs and time. To provide a tool, the Early Warning System (EWS) was developed by utilizing the Case Based Reasoning (CBR) approach. EWS is built to solve potential lawsuits caused by change orders using past resolutions based on data collection of this research. It was conducted in the basis of litigation archives stored in the Supreme Courts and appellate courts in 48 states and one district of the United States. 340 out of 4818 litigation archives were accepted as complete data samples during investigation. EWS is a useful tool to cope with unpredictable and unstructured disputes produced by change orders. It not only displays warnings when ongoing projects encounter similar situations occurred in the past, but also provides information related to past cases that contain procedures of settling disputes initiated by change orders. Finally this research contributes that construction owners and contractors can utilize EWS databases as reference to prevent unnecessary expenditure by legal actions.