\ifthenelse {\boolean{paper}} { \abstract{ This paper describes how the Failure Mode Modular De-composition (FMMD) methodology can be applied to the problems of common mode failure analysis. % Common mode failures are often difficult to determine in embedded real time systems. % Environmental effects can lead to component failure modes, that can occur in separate sub-systems in a system, but interact to create unexpected fault. % WHAT IS DID The FMMD methodology can model and warn for two types of common mode failures. Failures caused by separate sub-systems relying on a common component, and environmental effects that can induce failure modes in components in separate sub-systems. % WHAT I FOUND From the FMMD data model it is possible to link the environmental effects and ensure determine the weak points in a design, where the failure modes may interact. For the component dependency case, the dependent component can be automatically highlighted by traversing the data model. % WHY YOU WOULD WANT TO READ IT This feature of FMMD proides another tool in the safety engineers repotiore, one that can shake out difficult to find common mode failure effects. } } { \paragraph{Chapter overview} This chapter describes how the % Failure Mode Modular De-composition (FMMD) FMMD methodology can be applied to the problems of common mode failure analysis. % Common mode failures are often difficult to determine in embedded real time systems. % Environmental effects can lead to component failure modes, that can occur in separate sub-systems in a system, but interact to create unexpected fault. % WHAT IS DID The FMMD methodology can model and warn for two types of common mode failures. Failures caused by separate sub-systems relying on a common component, and environmental effects that can induce failure modes in components in separate sub-systems. % WHAT I FOUND From the FMMD data model it is possible to link the environmental effects and ensure determine the weak points in a design, where the failure modes may interact. For the component dependency case, the dependent component can be automatically highlighted by traversing the data model. % WHY YOU WOULD WANT TO READ IT This feature of FMMD proides another tool in the safety engineers repotiore, one that can shake out difficult to find common mode failure effects. } \section{Introduction} {\huge MIGHT BECOME A PAPER IN ITS OWN RIGHT. WILL PROB BE PART OF DATA MODEL CHAPTER FOR NOW 22NOV2010 } \ifthenelse {\boolean{paper}} { paper } { chapter } Outline the fmmd process. Show modules with common dependencies (like on a power supply, a powersupply could have a fault like nopisy output) Trace a theoretical example and show how FMMD detects this (common dependency - like two {\dc}s being depemdent on the same failure mode. Then show an environmental effect, such as temperature and how it can induce faults in sepatate modulkes that would not be obviously related. Trace a theoretical example and show how FMMD detects this i.e. the environmental factor affecting both systems and causing a problem. what about the third way it can be affected. Like a chain of relays...... all could get welded .... think about that one.....