Safety-barrier diagrams and “bow-tie” diagrams have become popular methods in risk analysis and safety management. This paper describes the syntax and principles for constructing consistent and valid safety-barrier diagrams. The latter's relation to other methods such as fault trees and Bayesian Networks is discussed. Important advantages of safety-barrier diagrams as compared to other graphical risk-analysis methods are, firstly, the relative simplicity that supports communication with non-expert stakeholders and, secondly, the focus on deliberately inserted safety systems that supports the management and maintenance of these systems. Safety-barrier diagrams provide a useful framework for an electronic data structure that integrates information from risk analysis with operational safety management.