A method and system for analyzing equipment degradation for maintaining the equipment are provided. The method and system receive and store equipment and sensor data associated with operational equipment, generate a display signal to display a relationship analysis window, a residual error window, a performance condition window, and a maintenance trigger window, and evaluate a coordinated relationship between the equipment sensor data and the environmental data, determine residual errors and determine a Historical Health Condition Index (HHCI) for the operational equipment and generate a Future Health Condition Index (FHCI) from the HHCI, and generate an equipment maintenance trigger for the operational equipment by establishing a trigger threshold for maintenance.