<div dir="ltr">Thanks, Kevork. One learns something new every day!<div>I wouldn't introduce this complexity to our kids' DFDs and UCDs, however.</div><div><br></div><div>Cheers</div><div>Mark</div>
<div class="gmail_extra"><br><br><div class="gmail_quote">On 25 February 2013 13:24, Kevork KROZIAN <span dir="ltr"><<a href="mailto:kkrozian@ringwoodsc.vic.edu.au" target="_blank">kkrozian@ringwoodsc.vic.edu.au</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex">
<div lang="EN-AU" link="blue" vlink="purple">
<div>
<p class="MsoNormal"><span style="color:#1f497d">Hi James,</span></p>
<p class="MsoNormal"><span style="color:#1f497d"> </span></p>
<p class="MsoNormal"><span style="color:#1f497d">I just opened <i>Use Cases Requirements in Context</i> by Daryl Kulak and Eamonn Guiney and p 39 states:</span></p>
<p class="MsoNormal"><span style="color:#1f497d">“ It is often hard to decide which actors to show on a use case diagram. For example,, when a supplier provides an invoice to a company clerk and the clerk enters the invoice into the system, should the supplier
be included in the diagram ? If the supplier is shown it is called a <i>secondary</i> actor. Our rule is that the supplier should be shown in the diagram if the supplier’s behaviour impacts the system in any way. For example, if a supplier sends a shipment
late and that changes how the system reacts, then the supplier should be in the diagram.”</span></p>
<p class="MsoNormal"><span style="color:#1f497d"> </span></p>
<p class="MsoNormal"><span style="color:#1f497d">In a restaurant a waiter can’t interact with the ordering system until the customer places the order. A delay does not change the response from the system. The waiter would appear in the UCD but not the DFD
which would show the customer – the supplier or source of the data or the order. I wouldn’t place the waiter in the DFD as they are not the source of the data.</span></p>
<p class="MsoNormal"><span style="color:#1f497d"> </span></p>
<p class="MsoNormal"><span style="color:#1f497d">Perhaps you can offer details of your textbook if anyone wants to get a hold of it .
</span></p>
<p class="MsoNormal"><span style="color:#1f497d"> </span></p>
<p class="MsoNormal"><span style="color:#1f497d">Just my take on the discussion</span></p>
<p class="MsoNormal"><span style="color:#1f497d"> </span></p>
<p class="MsoNormal"><span style="color:#1f497d">Kind Regards</span></p>
<p class="MsoNormal"><span style="color:#1f497d"> </span></p>
<div>
<p class="MsoNormal"><span style="color:#1f497d">Kevork Krozian</span></p>
<p class="MsoNormal"><span style="color:#1f497d">IT Pathways Manager</span></p>
<p class="MsoNormal"><span style="color:#1f497d">Ringwood Trade Training Facility
</span></p>
<p class="MsoNormal"><span style="color:#1f497d">Tel: 0419 356 034</span><span style="color:#1f497d"></span></p>
</div>
<p class="MsoNormal"><span style="color:#1f497d"> </span></p>
<div>
<div style="border:none;border-top:solid #b5c4df 1.0pt;padding:3.0pt 0cm 0cm 0cm">
<p class="MsoNormal"><b><span lang="EN-US" style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">From:</span></b><span lang="EN-US" style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> <a href="mailto:sofdev-bounces@edulists.com.au" target="_blank">sofdev-bounces@edulists.com.au</a> [mailto:<a href="mailto:sofdev-bounces@edulists.com.au" target="_blank">sofdev-bounces@edulists.com.au</a>]
<b>On Behalf Of </b>Vella, James<br>
<b>Sent:</b> Monday, 25 February 2013 10:56 AM<br>
<b>To:</b> <a href="mailto:sofdev@edulists.com.au" target="_blank">sofdev@edulists.com.au</a><br>
<b>Subject:</b> Re: [Year 12 SofDev] DFDs</span></p>
</div>
</div>
<p class="MsoNormal"> </p>
<div>
<p><a name="13d134b7f6f50ba7_13d0f2be36291d32__MailEndCompose"><span lang="EN-US">Strictly speaking as someone who did DFDs at uni…</span></a><span lang="EN-US"></span></p>
<p><span lang="EN-US"> </span></p>
<p><span lang="EN-US">As Mark has said, we sometimes think in a human sense however DFDs don’t allow us to see the interactions between two EEs.</span></p>
<p><span lang="EN-US"> </span></p>
<p><span lang="EN-US">As Selina has said, the waiter is just the input method – so we can leave it out. I think our students sometimes find it hard at this stage where they have to decide what should and shouldn’t be included in our DFDs.
</span></p>
<p><span lang="EN-US"> </span></p>
<p><span lang="EN-US">In terms of the DFD, you could argue either way for one or the other….but NOT BOTH!
</span><span lang="EN-US" style="font-family:Wingdings">J</span><span lang="EN-US"></span></p>
<p><span lang="EN-US"> </span></p>
<p><span lang="EN-US">That being said, in the UCD you can list both as actors because they both have roles in the system.</span></p>
<p><span lang="EN-US"> </span></p>
<p><span lang="EN-US">I have a whole text book on this stuff from my 2<sup>nd</sup> year at LaTrobe which I’m using with my kids at the moment…DFDs, UCDs, UML the whole kit and caboodle!</span></p>
<p><span lang="EN-US"> </span></p>
<p><span lang="EN-US">Regards</span></p>
<p><span lang="EN-US"> </span></p>
<p><span lang="EN-US">Mr James Vella</span></p>
<p><span lang="EN-US">MacKillop College</span></p>
<p><span lang="EN-US"> </span></p>
<p><span lang="EN-US"> <snip></span></p></div></div></div></blockquote></div><div dir="ltr"><div style><br></div><div style>Mark Kelly</div><div style><a href="mailto:mark@vceit.com">mark@vceit.com</a></div></div>
</div></div>