Object Oriented Analysis (OOA)
Object Oriented Approach or Programming (OOA or OOP)
OBS (Organization Breakdown Structure)
Ocean Thermal Energy Conversion (OTEC)
Octane Number or Octane Rating
OECD (Organization for Economic Cooperation and Development)
OEM (Original Equipment Manufacturer)
Office Information System (OIS)
Office of Environmental Management (EM)
Offshore Geotechnical Engineering
Offshore Platform (or Offshore Drilling Rig)
(OFGEM) Office of Gas and Electricity Markets
One Line Diagram or Single Line Diagram (SLD)
Online Document Management System
Online to Offline (O2O) Commerce
OPEC (Organization of the Petroleum Exporting Countries)
Open Loop Geothermal Heat Pump System
Operating & Maintenance Manual
Operating Gas Lift Valve (OGLV)
Operations Readiness and Assurance (OR&A)
OPEX (Operational expenditure)
OS&D (Overage, Shortage and Damage)
OSHA (Occupational Safety and Health Administration)
OSHA Process Safety Management (OSHA PSM)