Planned Maintenance Systems.
Source: International Association of Drilling Contractors, Appendix 2 to Health, Safety and Environment Case Guidelines for Offshore Drilling Contractors, Issue 3.3.2, February 2010. IADC Guidelines
Source: NOGEPA Industrial Guideline No. 43, Surface BOP Review, Best Practices Checklist, Netherlands, Version 0, December 2011. Global Standards
Source: Oil & Gas UK, Guidelines on subsea BOP systems, Issue 1, July 2012, Global Standards