Condition monitoring and fault diagnosis is the groundwork of condition-based maintenance, and much research has been done about diagnostic algorithm and monitoring manufactures, but less research about diagnostics strategy and management. Plenary diagnostics based on event driven threads of data propagated through successive diagnostic levels is an improving attempt about it. In this approach, abnormities are firstly detected or isolated in operational level. Then the anomalous event data is transmitted from low diagnostic level to higher levels, collected and centrally analyzed and finally fed back as diagnostic updates to improve diagnosis modules. This paper describes the diagnostic data flow and the management strategy of plenary diagnostics, and the difference between which and conventional diagnostics strategy. Finally, an example about power equipments fault diagnosis is given.Index Terms--abnormity, condition monitoring event driven threads, fault, field level, intermediate level, logistics data system (LDS), operational level, plenary diagnostics power equipments