Re: [SystemSafety] Modelling and coding guidelines: "Unambiguous Graphical Representation" from paul_e.bennett_at_xxxxxx <style type="text/css"> /*<![CDATA[*/ /* To be incorporated in the main stylesheet, don't code it in hypermail! */ body {color: black; background: #ffffff} dfn {font-weight: bold;} pre { background-color:inherit;} .head { border-bottom:1px solid black;} .foot { border-top:1px solid black;} th {font-style:italic;} table { margin-left:2em;}map ul {list-style:none;} #mid { font-size:0.9em;} #received { float:right;} address { font-style:inherit ;} /*]]>*/ .quotelev1 {color : #990099} .quotelev2 {color : #ff7700} .quotelev3 {color : #007799} .quotelev4 {color : #95c500} .period {font-weight: bold} </style> </head> <body> <div class="head"> <h1>Re: [SystemSafety] Modelling and coding guidelines: "Unambiguous Graphical Representation"</h1> <map id="navbar" name="navbar"> <ul class="links"> <li> <dfn>This message</dfn>: [ <a href="#start2276" name="options1" id="options1" tabindex="1">Message body</a> ] [ More options (<a href="#options2">top</a>, <a href="#options3">bottom</a>) ] </li> <li> <dfn>Related messages</dfn>: [ <a href="2277.htm" accesskey="d" title="Steve Tockey: "Re: [SystemSafety] Modelling and coding guidelines: "Unambiguous Graphical Representation""">Next message</a> ] [ <a href="2275.htm" title="Matthew Squair: "Re: [SystemSafety] Modelling and coding guidelines: "Unambiguous Graphical Representation""">Previous message</a> ] [ <a href="2271.htm" title="Les Chambers: "Re: [SystemSafety] Modelling and coding guidelines: "Unambiguous Graphical Representation""">In reply to</a> ] [ <a href="2300.htm" accesskey="t" title="Les Chambers: "Re: [SystemSafety] Modelling and coding guidelines: "Unambiguous Graphical Representation""">Next in thread</a> ] [ <a href="#replies">Replies</a> ] </li> </ul> </map> <ul class="links"> <li><a name="options2" id="options2"></a><dfn>Contemporary messages sorted</dfn>: [ <a href="date.htm#msg2276" title="Contemporary messages by date">by date</a> ] [ <a href="index.htm#msg2276" title="Contemporary discussion threads">by thread</a> ] [ <a href="subject.htm#msg2276" title="Contemporary messages by subject">by subject</a> ] [ <a href="author.htm#msg2276" title="Contemporary messages by author">by author</a> ]</li> </ul> </div> <div class="mail"> <address class="headers"> <span id="from"> <dfn>From</dfn>: < > </span><br /> <span id="date"><dfn>Date</dfn>: Wed, 02 Mar 2016 12:18:14 +0000</span><br /> </address> <br /> <br> On 02/03/2016 at 11:22 AM, "Les Chambers" <les_at_xxxxxx <br> <i class="quotelev1">></i><br> <i class="quotelev1">>Sounds interesting. The components are one thing. What about </i><br> <i class="quotelev1">>emergent properties of the assembled whole. How do you review the </i><br> <i class="quotelev1">>interactions. The modern zeitgeist seems to be developing systems </i><br> <i class="quotelev1">>of dumb objects that interact. The problem is that the complexity </i><br> <i class="quotelev1">>gets pushed into the interaction. This is an abstract thing. Very </i><br> <i class="quotelev1">>hard to pick apart in a review. Have you any solutions for this?</i><br> <p> I shall relay this in an analogy from the mechanical world. <p> The humble nut and bolt are a pair of components that, according to their data-sheet will exist in a specific environment and be able to be tightened up to a specific toque figure to serve throughout its designated lifetime. <p> We can use the nut and bolt in a more complex assembly (such as a carburettor for a car) which will perform as indicated in the manufacturers data-sheet as part of the engine component. <p> The emergent behaviour and failure modes become known through the design process and with the inspection and testing that ensures the final product is as described. Using only certified components and frequent review stages throughout the design keeps the behaviour (designed or emergent) within bounds. <p> The entire system (the car) is designed around a multitude of components (probably all selected from a catalogue of components that have proven themselves over time). <p> Note that this analogy is based on vehicle manufacturing before electronics or software became involved. The question I always pose is why electronics and software could not be as certain in its development as those early vehicle designs. <p> I know it is possible as my electronics and software have survived with zero maintenance effort for more than 20 years (one software system is now operational since 1985 and has just had operational life extension granted until 2030) within very harsh operational environments. <p> Regards <p> Paul E. Bennett IEng MIET <br> Systems Engineer <pre> -- ******************************************************************** Paul E. Bennett IEng MIET.....<email://Paul_E.Bennett_at_xxxxxx Forth based HIDECS Consultancy.............<<a href="http://www.hidecs.co.uk">http://www.hidecs.co.uk</a>> Mob: +44 (0)7811-639972 Tel: +44 (0)1392-426688 Going Forth Safely ..... EBA. www.electric-boat-association.org.uk.. ******************************************************************** _______________________________________________ The System Safety Mailing List systemsafety_at_xxxxxx </pre> <span id="received"><dfn>Received on</dfn> Wed Mar 02 2016 - 13:18:24 CET</span> </div> <div class="foot"> <map id="navbarfoot" name="navbarfoot" title="Related messages"> <ul class="links"> <li><dfn>This message</dfn>: [ <a href="#start2276">Message body</a> ]</li> <li><dfn>Next message</dfn>: <a href="2277.htm" title="Next message in the list">Steve Tockey: "Re: [SystemSafety] Modelling and coding guidelines: "Unambiguous Graphical Representation""</a></li> <li><dfn>Previous message</dfn>: <a href="2275.htm" title="Previous message in the list">Matthew Squair: "Re: [SystemSafety] Modelling and coding guidelines: "Unambiguous Graphical Representation""</a></li> <li><dfn>In reply to</dfn>: <a href="2271.htm" title="Message to which this message replies">Les Chambers: "Re: [SystemSafety] Modelling and coding guidelines: "Unambiguous Graphical Representation""</a></li> <li><dfn>Next in thread</dfn>: <a href="2300.htm" title="Next message in this discussion thread">Les Chambers: "Re: [SystemSafety] Modelling and coding guidelines: "Unambiguous Graphical Representation""</a></li> <li><a name="replies" id="replies"></a> <dfn>Reply</dfn>: <a href="2300.htm" title="Message sent in reply to this message">Les Chambers: "Re: [SystemSafety] Modelling and coding guidelines: "Unambiguous Graphical Representation""</a></li> </ul> <ul class="links"> <li><a name="options3" id="options3"></a><dfn>Contemporary messages sorted</dfn>: [ <a href="date.htm#msg2276" title="Contemporary messages by date">by date</a> ] [ <a href="index.htm#msg2276" title="Contemporary discussion threads">by thread</a> ] [ <a href="subject.htm#msg2276" title="Contemporary messages by subject">by subject</a> ] [ <a href="author.htm#msg2276" title="Contemporary messages by author">by author</a> ]</li> </ul> </map> </div> <p><small><em> This archive was generated by <a href="http://www.hypermail-project.org/">hypermail 2.3.0</a> : Wed Feb 20 2019 - 01:17:08 CET </em></small></p> </body> </html>