October 2007
Monthly Archive
The Sleeping Doll
Posted by georgemc on 27 Oct 2007 | Tagged as: books
One thing I like about travel is buying the “airport” paperback versions of new hardbacks you can get at Heathrow Terminal 4, and since I am on a trip to New Orleans at the moment, that explains why I just reviewed the new Rebus and now the new Deaver, The Sleeping Doll.
Deaver has a new heroine, Kathryn Dance, briefly introduced in the last Rhyme story, whose forte is reading body language. I read this in one sitting while flying from Heathrow to Houston (modulo a crappy stop at Detroit where we had to go through immigration and customs before reboarding the same aircraft - BA did not mention this on the website when I booked the ticket - grrrr).
Back to the new Deaver: I liked every aspect of it. The plot was twistier than the bad guy was twisted and twisting, and the focus on behaviour rather than forensics worked for me; I look forward to more Dance as well as Rhyme. I can’t publish my only criticism without danger of a plot spoiler, so ask me once you’ve read it, and with curious coincidence, the same criticism applies to the latest Rebus. One clue: Michael Connelly has used the same plot device in at least one Bosch story and I’m getting a little tired of it.
Exit Music
Posted by georgemc on 27 Oct 2007 | Tagged as: books
Ian Rankin’s latest Rebus novel “Exit Music” twists and turns through both plot and Edinburgh in the fine style we’ve come to expect. I say “latest” rather than “last” since although this book charts his final days as a police detective, it is possible that the franchise will continue through Siobhan or even Rebus himself in another mode (I seem to recall that TV’s “Taggert” managed to continue even after Taggert was dead).
Anyway, if Rankin did decide to stop the Rebus series with this one, it would be on a splendid high note - highly recommended.
Gold Plating (as revealed by Requirements Traceability Analysis)
Posted by georgemc on 18 Oct 2007 | Tagged as: graphics, Perspector, hierarchy, PowerPoint, business, 3D, requirements, presentations, traceability
Gold Plating is a concept from requirements management which for some strange reason I find amusing. Gold plating is simply the creation of “stuff” which it has not been agreed satisfies any stated need. We might be lucky and the gold plated “stuff” turns out to be useful. On the other hand we may end up seeing an ashtray on a motorbike.
With pleasing symmetry to my last posting about knowing when you are finished, gold plating turns out to be just another report, but at the lower implementation level:
with respect to the SR, gold plating in the “slides” is identified by finding any slide which does not have an outgoing satisfaction link and drawing a red box around it, as we have done for the white elephant. This corresponds to the situation where the owner of the SR has outsourced the implementation of the SR as the creation of slides, and is interested in tracking what is happening. The contractor has not yet proposed a satisfaction link for the white elephant, perhaps because they know that any such link would not be agreed meets a stated need in the SR (the SR owner gets to decide whether satisfaction links are good or not).
My postings on RM traceability are informed from my experience of talking to systems engineering consultants and practitioners who know what they are doing on very large systems and budgets, and so I am comfortable that at least some people in the world are happy to invest in a requirements management process where you actually do write down requirements and make links between them and with other life cycle assets. For my next RM posting project, I’m going to think about how to spread the word to those folks who would rather cut their own heads off than write down a requirement, never-mind user, system and test requirements.
Using Requirements Traceability to Know When You are Finished
Posted by georgemc on 14 Oct 2007 | Tagged as: graphics, Perspector, hierarchy, PowerPoint, 3D, requirements, presentations, traceability
An important application of traceability is to let you assess how complete your project is - and not just with a binary “yes I am finished” or “no, still work to do”. We can use the presence or absence of approved traceability links to to measure progress at a much finer level of granularity, and in terms of both qualification (is this bit tested yet?) and satisfaction (has something lower down been built which satisfies this need?). Consider the link between SR:16 and the slide which depicts a “bored audience”, highlighted below (the idea being that the “bored audience” slide may contribute some humor to the presentation):
If for some reason the contractor who is doing the slides for the person who is responsible for the SR had not yet proposed this satisfaction link (i.e., let’s delete it), the SR owner may be interested in running a report which shows all requirements which are not linked by approved satisfaction links:
If your SR is full of red boxed requirements, then you know you are far from finished (notice that SR:1 also has no incoming satisfaction links, so it too is highlighted with a red box).
Yet More on Requirements Traceability
Posted by georgemc on 12 Oct 2007 | Tagged as: graphics, Perspector, hierarchy, business, 3D, requirements, traceability
Further to my second post on this topic, I’ve been working away at the detail of my example scenario so that it hangs together better.
I am discovering that it takes a lot of work to create even a “toy” requirements traceability example, but I think I am getting close. As I did before, I shall start with the “end result diagram” which you can now click on to get to a more detailed version:
In a couple of weeks I shall be presenting at the PowerPoint Live User Conference in New Orleans. The subject I am speaking about is how applying principles from requirements management (RM) can help us build better presentations. Since the audience already understands a lot about presentations, I thought I’d illustrate RM by applying one of its formal information models to the construction of the presentation that they will be watching me give. Here’s another, more refined sneak preview, beginning with:
My UR above contains just an illustrative sample of 4 user requirements; my real talk covers 10 principles of requirements management and I can imagine writing down other requirements on the presentation such as that it will be between 45 and 52 minutes long. The first thing to note about user requirements is that they should try not to mention solutions (like using slides) - they should contain only things you want to achieve or constraints imposed by the environment (e.g. I only have one hour in the conference schedule).
A requirement that can’t be tested is not a proper requirement. So anytime you write or contribute to a user requirement, you should think about how it is going to be tested. And before getting directly into tests, you should do a bit of test planning; the ATP is a high level description of what the tests should achieve -it contains test requirements not tests. So here I decided that I am going to test the audience’s learning of the principles by an examination. ATP:11 is going to help us qualify that the audience was actually entertained by measuring something that may be an indicator of that.
For URD:15, we have an easier test requirement, ATP:15. We only need to demonstrate that further engagements are requested when that happens.
In the acceptance tests we specify tests which will be performed to qualify the acceptance test plan. Above we just show the test for assessing whether the audience understood the principle about distinguishing problems from solutions. In real systems development, one would not ask such blatantly leading questions!
Now we think about the system which we will build to satisfy the user requirements. And for the UR presented above we make the decision that images with commentary (i.e. a slide show) will be fit for purpose. To meet the requirement URD:15, which was about generating spin-off engagements, I’ve decided that one way of doing that will be to make sure that the audience is entertained, and one way of doing that is to employ humor in the slides and commentary. So even if the audience don’t understand what is being said or shown, if they have had a laugh now and then, they might still rate the presentation highly enough to secure further bookings for the presentation and/or the speaker.
and above we see a sample of 4 slides which will be used to satisfy requirements in the SR. The slides are our final implementation layer (we don’t bother with test plan and tests for this layer of our example).
The SR requires a system test plan to qualify its system requirements. STP:1 is about testing to see whether 90% the audience “believes” that the images and commentary successfully explain the concepts they are being used to portray. This is a much weaker test than examining their actual understanding!
Our last document is the system tests, where we specify how to test the system test requirements in the STP. I was worried that measuring how often people smile was maybe a too crazy idea for even a toy example, but then I remembered how much importance Hollywood places on the results of measuring the reaction of test audiences to movies - so my example is maybe not so contrived after all.
At last we can show what traceability is by linking the requirements, test requirements and tests together, which leads us back to the first image again:
(please click the image for more detail).
In this trip out to tackle traceability, I’ve pushed to three levels, so there are now two sets of satisfaction links; the first is between the SR and the UR, and the second is between the slides (aka SSR or implementation) and the SR. Three of the slides help satisfy SR:2, one of the slides helps satisfy SR:16 (humor), you can’t really see what the image providing humor is, but its title is “bored audience”.
There is much more that can be said about the above traceability diagram, but for now I am happy I’ve created a firmer foundation for having those conversations in future posts.