This paper describes BPA's experience with a BPA-developed automatic performance monitoring system which monitors pertinent operational parameters of seven major BPA microwave systems. This Microwave Monitor (MWM) system provides Operations and Maintenance personnel with continuous measurement of each system's performance. With the MWM, gradual system degradation and impending failures are detected before an outage occurs. This allows maintenance visits to be scheduled in advance. Also, the MWM isolates problems to specific sections of each microwave system, allowing rapid location and repair. The MWM system performs automatic diagnosis, and only requires remote terminals at the ends of each microwave system. Having gained operational experience over several years, BPA can now confidently use the MW Monitor to evaluate BPA maintenance approaches and procedures.