Handbook of Reliability, Availability, Maintainability and Safety in Engineering Design - Part 76 studies the combination of various methods of designing for reliability, availability, maintainability and safety, as well as the latest techniques in probability and possibility modelling, mathematical algorithmic modelling, evolutionary algorithmic modelling, symbolic logic modelling, artificial intelligence modelling, and object-oriented computer modelling, in a logically structured approach to determining the integrity of engineering design. . | 734 5 Safety and Risk in Engineering Design g Networks - SYSTEMO VALVE1 VALVE 2 VALVE3 VALVE4 Fault Trees g F Aie Models VALVES1-2 VALVES3-4 B DataSets VALVES - Consequences LOSS - Spare Parts VALVE g ft Labori Categories Î DIVER OPERATOR g 0 Phases 0A 0B V Bitmaps Networks Fault Trees X Weibull Analysis X Results valve1 Control valve ETA 12387 4. 30M Qrn VALVE2 Control valve ETA-12387 4. 30 Qm-0 003115 VALVE3 Control valve ET A-12387 4. 20 Qm-0 3150 VALVE4 _ Control valve E TA 12387 4. 20 Qm-O3Oe2 PRO RAM RELIABILITY AVAILABILITY MAINTAINABILITY EXPERT SYSTEM BLACKBOARD FOR ENGINEERING DESIGN REVIEW AvSm Protect HIPS Parallel Control Valve Assembly Fig. Monte Carlo simulation of RBD and FTA models During the simulation process the model will be able to determine whether the system will fail by examining the developed network diagram. The model does this by determining whether there are any open paths from the input node or block to the output node or block. An open path is a path that does not cross any failed component or sub-system blocks. Network diagrams may also be used to represent voting arrangements. Nodes to the right of a parallel arrangement may be given a vote number to indicate how many success paths must be available through the parallel arrangement if a vote number is not specified then only one path need be available . The simple parallel arrangement of the four blocks 1 2 3 and 4 in Fig. with a vote number number of available paths required for success of 2 would result in the truth table given in Table . Figure illustrates the use of the fault-tree diagram in determining potential system failures in a parallel control valve configuration of a high-integrity protection system HIPS . This is developed from the imbedded Isograph AvSim Availability Simulation Model Isograph 2001 . Fault-tree diagrams graphically represent the interaction of failures and other events within a system. Basic events at the bottom of the .
