This International Standard describes:

• the requirements to apply when reliability block diagrams (RBDs) are used in dependability analysis;

• the procedures for modelling the dependability of a system with reliability block diagrams;

• how to use RBDs for qualitative and quantitative analysis;

• the procedures for using the RBD model to calculate availability, failure frequency and reliability measures for different types of systems with constant (or time dependent) probabilities of blocks success/failure, and for non-repaired blocks or repaired blocks;

• some theoretical aspects and limitations in performing calculations for availability, failure frequency and reliability measures;

• the relationships with fault tree analysis (see IEC 61025 [1]) and Markov techniques (see IEC 61165 [2]).