\ifthenelse {\boolean{paper}} { \abstract{ This paper describes how the FMMD methodology can be applied throughout the lifecycle of a product, with minimal impact to the cost of re-analysis. % what I did Looking at SYSTEMS ENGINEERING concepts. FMMD static design analysis tool, but can be applied to product life cycle Becomes a living analysis tool % what I found Alterations required in a failure mode model arise from new failure modes discovered in base components, new failure mode behaviour observed in {\dc}s, and environmantal effects found that interact with the failure mode model. % conclusion FMMD analysis can be updated with these three effects and we can apply procedures that will automaically force the uncoverig of new possible SYSTEM failure modes. } } { This chapter describes how the FMMD methodology can be applied throughout the lifecycle of a product, with minimal impact to the cost of re-analysis. % what I did Looking at SYSTEMS ENGINEERING concepts. FMMD static design analysis tool, but can be applied to product life cycle Becomes a living analysis tool % what I found Alterations required in a failure mode model arise from new failure modes discovered in base components, new failure mode behaviour observed in {\dc}s, and environmantal effects found that interact with the failure mode model. % conclusion FMMD analysis can be updated with these three effects and we can apply procedures that will automaically force the uncoverig of new possible SYSTEM failure modes. } \section{Introduction} \ifthenelse {\boolean{paper}} { paper THIS IS THE PAPER VERSION OF THE CHAPTER QUICK DESCRIPTION OF FMMD } { chapter THIS IS THE CHAPTER IN THESIS VERSION OF THE CHAPTER } \section{Three sources of Alteration/addition to the FMMD Model} \subsection{discovering a `new' failure mode in a component} Give general idea of how a new failure mode can be integrated into the model. How it may cause a new symptom but may not. How it will generally be limited to small sections of th FMMD tree. Give specific example, pretend a new failure mode is discovered in a SCHOTTKY diode. Often an electronic component will have a new failure mode `discovered' I am using as an example a diode which has an exponential relationship with temperature and reverse leakage current. This is a failure mode that would not be initially considered in a design. But when combined with high value resistors could give incorrect voltage readings in some circuits. I how the FMMD model can have this new failure mode added and what impact it has on the FMMD data model. \subsection{Discovering New Failure Mode behaviour in a {\dc}} Ref Nacy Leveson, system eng. A sub-system or system has its own behaviour etc These may be traced to combinations of afailure modes but may be undiscovered in initial analysis. \subsection{New or additional evironmental Conditions} An environmental effect may be found to affect a sub-system. Show how this vcan be retro fitted into a working/live FMMD model. \section{Conclusion} Product Life cycle phases for FMMD