[Year 12 SofDev] U3O2 module context diagram

[Mark KELLY]

Thanks, Selina.  That makes sense. I'm working from a classic SRS template
and need to decide what to keep and what to toss, and I've already tossed a
lot.

Stop sniggering.

Perhaps a complete removal of the context diagram would be be more sensible
than an unsatisfactory compromise.

Regards

Mark

On 9 May 2011 18:36, Selina Dennis <selina at dennis.net.au> wrote:

> Hi Mark,
>
>
>
> My suggestion would be to not provide/require a context diagram here. As
> you’re not talking about a high level “view” of the entire system when
> you’re looking at a single function to calculate costs, a context diagram
> wouldn’t be the most appropriate diagram for students to
> represent/interpret. Realistically you’d be talking about a DFD Level X
> (where X would vary depending on the complexity of the entire system).
> Thus, entities don’t need to be shown, only the data flows entering and
> exiting.
>
>
>
> Hope that helps,
>
>
>
> Selina Dennis
>
> Strathmore Secondary College
>
>
>
> *From:* sofdev-bounces at edulists.com.au [mailto:
> sofdev-bounces at edulists.com.au] *On Behalf Of *Mark KELLY
> *Sent:* Monday, 9 May 2011 3:12 PM
>
> *To:* Year 12 Software Development Teachers' Mailing List
> *Subject:* Re: [Year 12 SofDev] U3O2 module context diagram
>
>
>
> I'm tempted to use the simple version since dataflows between external
> entities (EE) is verboten.
>
> The problem is that it implies that the customer directly provides data to
> the module, whereas the website and system pass the data on before the
> module becomes involved. The CD with the EE-to-EE flows would be more
> informative and accurate, but it breaks our rules...
>
> It's a wrinkle I haven't faced before with context diagrams.
>
> On 9 May 2011 14:31, Esther Andrews <ANDREWS.Esther at bssc.edu.au> wrote:
>
> Funny how the apparently simple can end up being complex.
>
> Given your description I’d say the customer does not directly provide input
> into the system so should not be on the Context diagram.
>
> Esther
>
>
>
> *From:* sofdev-bounces at edulists.com.au [mailto:
> sofdev-bounces at edulists.com.au] *On Behalf Of *Mark KELLY
> *Sent:* Monday, 9 May 2011 2:13 PM
> *To:* Year 12 Software Development Teachers' Mailing List
> *Subject:* [Year 12 SofDev] U3O2 module context diagram
>
>
>
> Hi all. I',m adapting the detailed example of SD U3O2 from the study design
> for my own U3O2; I'm fiddling at the edges and not changing the overall
> shape of the example where the task is to create a specific module (cost
> calculator) in a larger ordering/accounting system that takes order data
> from a corporate website.
>
>
>
> While getting into creating the SRS I thought the context diagram would be
> a doddle.  One external entity, the customer.  The system in the circle  is
> the cost calculator module.  One data flow from the customer with order
> information. One data flow to the customer with the invoice. Done.
>
> Then I realised that from the module's perspective the rest of the ordering
> system might be seen as an external entity since the module has no control
> over the system's operation but must exchange data with it.
>
> Then I realised that the system also would see the corporate website as an
> external entity for similar reasons. So the customer would interact with the
> website which would interact with the system, which would interact with the
> module that the students will be writing.
>
> But if I showed the customer providing an order to the website, that would
> be a data flow between external entities which we are not supposed to show
> in a CD/DFD.
>
> How would you guys interpret a situation like this?
>
> --
> Mark Kelly
> Manager of ICT, Reporting, IT Learning Area
> McKinnon Secondary College
> McKinnon Rd McKinnon 3204, Victoria, Australia
> Direct line / Voicemail: +613 8520 9085, Fax +613 9578 9253
> kel at mckinnonsc.vic.edu.au
> VCE IT Lecture Notes: http://vceit.com
> Moderator: IT Applications Edulist
>
> Want a good time? Call 0112358. Ask for Mr Fibonacci.
>
>
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>
>
>
>
> --
> Mark Kelly
> Manager of ICT, Reporting, IT Learning Area
> McKinnon Secondary College
> McKinnon Rd McKinnon 3204, Victoria, Australia
> Direct line / Voicemail: +613 8520 9085, Fax +613 9578 9253
> kel at mckinnonsc.vic.edu.au
> VCE IT Lecture Notes: http://vceit.com
> Moderator: IT Applications Edulist
>
> Want a good time? Call 0112358. Ask for Mr Fibonacci.
>
> _______________________________________________
> http://www.edulists.com.au - FAQ, Subscribe, Unsubscribe
> IT Software Development Mailing List kindly supported by
> http://www.vcaa.vic.edu.au - Victorian Curriculum and Assessment Authority
> and
> http://www.vcaa.vic.edu.au/vce/studies/infotech/softwaredevel3-4.html
> http://www.vitta.org.au  - VITTA Victorian Information Technology Teachers
> Association Inc
>



-- 
Mark Kelly
Manager of ICT, Reporting, IT Learning Area
McKinnon Secondary College
McKinnon Rd McKinnon 3204, Victoria, Australia
Direct line / Voicemail: +613 8520 9085, Fax +613 9578 9253
kel at mckinnonsc.vic.edu.au
VCE IT Lecture Notes: http://vceit.com
Moderator: IT Applications Edulist

Want a good time? Call 0112358. Ask for Mr Fibonacci.
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