This work investigates and develops an approach to resolve some of the unique challenges associated with condition monitoring variable duty equipment. The proposed solution utilizes the mechanical redundancy of parallel systems to create dynamic criterion for detecting incipient faults. In this context, parallel systems are those which contain multiple subsystems (with similar construction) having synchronized operating conditions. This work evaluates the proposed methodology through its application on parallel hydraulic gear pumps. By comparing the dynamic pressure and vibration signal features, it was found that this approach is capable of distinguishing various incipient failures while the pumps were in both stationary and non-stationary operation.