Abstract: A method of performing preventative, routine and repair maintenance on a plurality of geographically remote units includes the step of establishing a Common Core System (CCS), or portion of a unit under test (UUT) component that has a common configuration for each unit. The CCS can be established at manufacture, or it can be back fitted by hardware implementation on legacy UUT's. Each CCS is networked to an Advanced Automated Test System (AATS), which is further networked to a central knowledge database and to a plurality of remote users. The remote users can access the AATS through the network to conduct remote tests of the UUT through the CCS, and to troubleshoot the UUT in response to a UUT test fault. The central knowledge database can further store configuration and operation history for the UUT, to maintain configuration control and to predict a Mean Time Between Failures (MTBF) for the UUT.