From 148bc7cba947e26e640ee9cf4fc794ed0adc946c Mon Sep 17 00:00:00 2001 From: "Robin P. Clark" Date: Thu, 2 Apr 2015 10:17:46 +0100 Subject: [PATCH] added a sw_hw_hierarchy diagram and description --- papers/JOURNAL_fmea_sw_hw/Makefile | 8 ++++-- papers/JOURNAL_fmea_sw_hw/sw_hw_fmea.tex | 27 +++++++++++++++++- papers/JOURNAL_fmea_sw_hw/sw_hw_hierarchy.dia | Bin 0 -> 1849 bytes 3 files changed, 32 insertions(+), 3 deletions(-) create mode 100644 papers/JOURNAL_fmea_sw_hw/sw_hw_hierarchy.dia diff --git a/papers/JOURNAL_fmea_sw_hw/Makefile b/papers/JOURNAL_fmea_sw_hw/Makefile index 6a516c7..4ecab51 100644 --- a/papers/JOURNAL_fmea_sw_hw/Makefile +++ b/papers/JOURNAL_fmea_sw_hw/Makefile @@ -1,11 +1,15 @@ -PNG = fmmdh.png ct1.png hd.png ftcontext.png +# dia PNG is broken, text mangled // PNG = fmmdh.png ct1.png hd.png ftcontext.png +JPG = fmmdh.jpg ct1.jpg hd.jpg ftcontext.jpg sw_hw_hierarchy.jpg %.png:%.dia dia -t png $< +%.jpg:%.dia + dia -t jpg $< -all: ${PNG} + +all: ${JPG} pdflatex sw_hw_fmea pdflatex sw_hw_fmea acroread sw_hw_fmea.pdf || okular sw_hw_fmea.pdf || xpdf sw_hw_fmea.pdf diff --git a/papers/JOURNAL_fmea_sw_hw/sw_hw_fmea.tex b/papers/JOURNAL_fmea_sw_hw/sw_hw_fmea.tex index 4e91c2b..292180d 100644 --- a/papers/JOURNAL_fmea_sw_hw/sw_hw_fmea.tex +++ b/papers/JOURNAL_fmea_sw_hw/sw_hw_fmea.tex @@ -225,7 +225,7 @@ examining all known failure modes in the context of the system that it is part o Various handbooks and international standards list common components and their know failure modes, often with accompanying statistics~\cite{en298, fmd91, mil1991}. -\subsection{Origins of FMEA tecniques} +\subsection{Origins of FMEA techniques} %FMEA methodologies trace from the 1940's and were designed to %model simple electro-mechanical systems. % @@ -243,8 +243,33 @@ software elements. %This paper explores the historical reasons why FMEA is performed in the way it is currently and %the new factors placing higher demands upon it. % +A control system designed up to the mid 1960's would typically have had no +programmatic/software elements. + + Software generally sits on top of most modern safety critical control systems and defines its most important system wide behaviour and communications. +% +A typical control system, be in in a car or a microwave oven in the kitchen +will generally combine a micro-controller with electronics. +It will form a hierarchy where low level electronics +is implemented at the bottom, which prepares input/output (IO) +signals for/from the micro controller. +The micro controller will have software to read/send signals to the electronics +and on top of that a functional software layer where the control algorithms will +reside. On the top of this hierarchy are the \cf{main} and \cf{monitor} functions. +This hierarchy is represented in figure~\ref{fig:sw_hw_hierarchy}. + +\begin{figure}[h]+ + \centering + \includegraphics[width=300pt]{./sw_hw_hierarchy.jpg} + % sw_hw_hierarchy.jpg: 814x412 pixel, 72dpi, 28.72x14.53 cm, bb=0 0 814 412 + \caption{Software and hardware hierarchy of a typical modern embedded control system.} + \label{fig:sw_hw_hierarchy} +\end{figure} + + + % Currently standards that demand FMEA investigations for hardware FMEA (HFMEA) (e.g. EN298, EN61508), do not specify FMEA for software but instead essentially just specify good practise, diff --git a/papers/JOURNAL_fmea_sw_hw/sw_hw_hierarchy.dia b/papers/JOURNAL_fmea_sw_hw/sw_hw_hierarchy.dia new file mode 100644 index 0000000000000000000000000000000000000000..5a110af32983f63ed57dbb66ce91a2bb4fcfcd35 GIT binary patch literal 1849 zcmV-92gdjxiwFP!000021MQsObJ{o%$KUxYH1y%x8CTenWy_^W=X!IUzI5)Pz2}@T z0(3PtV~eDDxxf9^KLQv`0vK^+&UBi@M$y-jclV%9N)V;-SVSc!M=f0~Lpg5QX<{OG1X(|Yl4FnD-)z|mtSbdusoEpa9X z|A;6O186kp-}VsN>|iXk$j?=0h1RJWEwx0kn9G~~NQB>~X|jyR{jycnE=-~%MfW1Q z>A#v3ul}IwW>D+rnZ6fdDo3dl-}iTI!z&0*>3Sj4?QZ9bBva5tKQ4Bf?CB@}y3wX; zl|iF;di&~E_f>gG)roaqO&7XXM9)P!Rq?J4%uQ5I1i_pT0+Yc49@xI?J5O_Ryxi!r za?xew(#y)J>~4{yIu%OqN{*5wk|Hiub-I+N>tvybz{H*#R*O+gl-9`$*FORGCyt-AlX z#x$yKa20Wo2(`L@I@*|%Wc0TTbv4+pTEt_Kj?r86G5OJ7uR&l1qQ*DFZur>O{b;n^dkWVt;%OwG6fBAZHlzf*mIFbaohBwDIll{& zG~QhvoNGLVL=i=H$Fzzd6jOWi<+RY6Nj076{bC&RnwIUKCN@gau}tskZrk9vj>!L= zrjgB(hr5P#>C4b<4iJO2Hyq#|-{cRy;U7-rA5LrkaByJx*kdL=q|~q(8#*rb31Jq; zo=r~F)cI7rfP<|z`)+Bmey+9KT55kyCi+37vbSf&{S2n|t$C7IH!0@l(L~Hu^avLw z;;fG{{g}s7h=t{^ewNX_)G8F4VgL9m*m24R$F#Q{({|g5)~)bBOFTtrI|dvS2Tl=! zh4D0=%jUZ&R#hiO|=-Byp zVmS=Ee7!sN^TPWx+<+Y3NN6O`WEn$BlEfnFfmQuAPsYngq`#m@-pi=NyJ@^Pm}`gk z>%+U-Hf#l$N@;6SEw+=FRM0Qd`$ z>I_9H(;eMS)4j=HJG@^X-o5tw?H1$-)MW0?iGWU+|N7CJIow+;M_Q7l&>>EwqS27N)gh_zyfE0(pRcyVlvUinZeIi0Qi?YE( z2Xo`8dZT@IIRBY(z9&}k*0G9V-{M9$<3YmX4z+yjbB{X1N|Nz_^PfLVb>YZ(INCA6 zE)-of6s;yIj%Bfhp6&S7(>rJe5vj6GofHK;X#MU@pYK*8ZFPEfra32HBcc?_&$YdfL=?edu8YKQDIBr?g2McuOD0$I$Cadr!b>)VoaTGu!dh#MBe#AJ{v ziij9?*pND)=C|4|d=cjDMsyI$Z5-6L38_Jp6KvN}&O4MJhw|1{cZ6VIR7G4{Q3=oTYKU`b|f1;}mbS%Z}q$$nn+{j}E&)WiVS; z22&qRt!U zRhTCE)}&68D3WPMa^oa#w#yFXSBUb~1&(=~VEK~-Mk|Hf{E1vv6bkV|4{{B&IBz+u zgLqCan3+46)S?9GGV>#O?w!F^0>7|bo0)Z%LWY3_gTH{M6xBi=7{E1D3$35-K{5&f z>ahwlR6OJ(GYe%3-pSA+l?#!|F`9tIEz%^ESq4Ap1cAwqyETCEXM7uNxmyBU;S#_< z!*jkKn1YWTvk&@uxrPlPEhzK?!%z9P8q-1i_b$qRUej{ij{nE;pP!)=#mh;|u}#cY zqm(*6c4_`myC0OQ&Q;{|zejRKeZYCecBJCPQV)`)hHo9-jpM!9R6D+3Vdb#XzJ|`j z6c&2~7-BMPtyG9zeE81ueMmSA*fr!WA4MinxO$cmJt#dx0*=vfGyI24KNEofj literal 0 HcmV?d00001