The term “barrier” has emerged as a prevailing and prominent concept in the field of offshore risk managementRisk management. It is frequently employed in various contextsContext, with significantly different meanings, such as human barrier, operational barrierOperational barrier, organizational barrierOrganizational barrier, technical barrierTechnical barrier and non-technical barrier. This variability suggests that achieving a consensus on a clear and uniform interpretation of the barrier concept is challenging. This lesson aims to clarify the concepts of the barrier and barrier management, along with the principles and process involved in barrier managementBarrier management. The foundation for this clarification is the set of guidance documents titled “Principles for Barrier Management in the Petroleum Industry” (Havtil in Principles for barrier management in the petroleum industry. Stavanger, Norway, 2013; Havtil in Barrier memorandum: principles for barrier management in the petroleum industry. Stavanger, Norway, 2017). In addition, this lesson addresses the regulatory requirements pertaining to barriers, as well as the structure principle of barriers and hazards. Lastly, the challengesChallenges faced in implementing barrier management are discussed.