MAR Consulting AS updated a Failure Modes, Effect, Criticality and Diagnostics Analysis (FMECA / FMEDA) of the hydraulic control and safety systems of a major drilling contractor’s subsea drilling BOP. MAR Consulting had performed the previous original FMECA / FMEDA based on API S53 4th Edition and the US Code of Federal Regulations (CFR). The new rig contract requires compliance with API S53 5th Edition and therefore warranted the update. And it is outside the Gulf of Mexico where the US CFRs are not applicable. This work is part of the partnership to develop a BOP digital twin and failure mode database for failure reporting to the authorities. Further details of previous projects awarded to MAR Consulting: FMEDA Deepwater drilling blow-out preventer · MAR Consulting; FMECA BOP subsea drilling safety system · MAR Consulting; FMEA of electrical and control systems in subsea BOP · MAR Consulting; FMECA / FMEDA subsea drilling BOP (electrical and hydraulic systems) · MAR Consulting; FMECA electrical and control systems in subsea BOP · MAR Consulting; FMECA of blow-out preventer hydraulic system · MAR Consulting.