Tutorial T4
T4: The Mechanical Generation of Fault Trees for State Transition Systems
Thursday 25th September, 13:30 - 17:00
Tutorial Leaders
Richard Banach (UK)
Marco Bozzano (IT)
Matthias Maruhn (DE)
Description
Fault Tree Analysis (FTA) is an indispensable tool in helping engineers understand system behaviour under degraded conditions. Given the specification of an undesired state (e.g. a failure state), FTA systematically builds all possible (minimal) chains of one or more basic faults, called (minimal) cut sets, that contribute to the occurrence of the event. The manual construction of fault trees for complex systems is a time-consuming activity, itself vulnerable to human error, encouraging automated techniques. This tutorial shows how formal techniques can be used to generate properly structured fault trees automatically, and discusses how this can be incorporated into current industrial practice. As such, both researchers and practitioners are encouraged to participate.
The tutorial first presents some background covering fault tree construction and their use in the safety and reliability process. It then introduces mechanical techniques for fault tree generation, that are exemplified and demonstrated by means of the FSAP toolset. Subsequently, the tutorial covers recent research on the retrenchment approach to mechanical fault tree construction via fault injection, in which retrenchments capture the relationship between nominal and faulty behaviours of basic components, and retrenchment theory underpins the derivation of richly structured fault trees for complex systems. The tutorial applies these techniques to fault tree derivation for digital hardware circuits of three kinds: instantaneous combinational logic circuits, clocked acyclic circuits, and clocked feedback circuits. The tutorial closes by comparing these techniques with the mechanical fault tree extraction routines available in FSAP.
Short Bios
Richard Banach has been in the School of Computer Science at the University of Manchester for over twenty years, over ten of which have been involved with the theory and applications of retrenchment.
Marco Bozzano holds a researcher position at Fondazione Bruno Kessler. He has been involved in several European projects dealing with the application of formal methods to safety and reliability. He is presently work package leader of the MISSA project, and working in two projects with the European Space Agency.
Matthias Maruhn worked in Daimler Chrysler's Research Department from 1995 to 2001, and since 2001 has been at Airbus Deutschland. He has been involved in system safety (A340 and A380) and safety policy application, and has participated in several European projects in safety and reliability, including MISSA.