When answering the question “What kind of Maritime Crisis Manage­ment System (MCMS) do we need?” a useful tool is provided by the system ap­proach. The traditional system approach, presented by the sequence “system goal (goals) definition – goal supporting strategy development – system technology and structure elaboration,” is not applicable to the process of MCMS analysis due to many reasons. The paper proposes an alternative method to study the MCMS func­tional aspects. The proposed approach describes the functioning of MCMS on the background of the Maritime Security Negative Factors (MSNF) evolution. The MSNF evolution is represented as a life cycle that follows the sequence: “emer­gence of maritime security challenges – evolution to risks – formation of threats.” The MCMS functioning is described by “Observation – Orientation – Decision – Action” (OODA) loops performed by the system in reaction to the negative factors and their evolution.