Real-time fault diagnostics and decision support system for rotary steerable system

A method comprising:

• disposing a rotary steerable system (RSS) into a borehole, wherein the RSS comprises:
• one or more sensors configured to measure a location of the RSS in a formation from one or more tracking measurements and monitor a mechanical operation of the RSS;
• and
• identifying a failure from the mechanical operation of the RSS or the one or more sensors from a diagnostic review, wherein the failure represents the failure of a device or part of a device disposed on the RSS;
• flagging the failure with a failure code;
• pairing the failure code and a failure mode with a dependency matrix, wherein a distance measure-based metric for fault isolation is combined with the dependency matrix and the failure code;
• and
• reporting the failure and its mitigation actions to personnel in real time.