A system strategy to estimation the guaranteed survivability and safety of complex engineering objects (CEO) operation is proposed. The principles that underlie the strategy of the guaranteed safety of CEO operation provide a °exible approach to timely detection, recognition, forecast, and system diagnostics of risk factors and situations, to formulation and implementation of a rational decision in a practicable time within an unremovable time constraint. Implementation of the proposed strategy is shown on example of diagnostics of electromobile-refrigerator functioning in real mode.