Starting with the Clean Air Act of 1970, there have been a number of dynamics in the natural gas compression industry that have posed challenges to operators of natural gas compression equipment - both from a technical and business perspective. One of these has been the development and utilization of higher speed, higher output natural gas engines to achieve exhaust emission regulations as the regulations have become more stringent. Another is to meet the demand for higher power density equipment. The technologies and controls needed to achieve these requirements have resulted in engines that are more complex than those used in the past. Business pressures to improve reliability and reduce costs have increased the challenge faced by operations and maintenance organizations as they acquire and maintain engines with the newer technology. At the same time that organizations are trying to adapt to these technology changes, many are also trying to control costs by reducing manpower at compressor sites and are trying to react to a changing workforce. Caterpillar has addressed these challenges by developing a Condition Monitoring service using the PI System to provide insight into emerging issues so that asset managers can make informed decisions on how and when to schedule corrective action.