Is there any use of the V-model?

I’m at the 13th International Conference on Agile Software Development in Malmö Sweden. As usual when I listen to presentations these tend to trigger new liner of thoughts instead of pondering the details of what was said. I guess this is a flaw in how I internalise knowledge from others.
Not surprising, nobody here mentioned the V-model. Too bad,since I think it is one of the most important metaphors regarding software (and system) development there is. But it is also on of the metaphors that have been used in ways which are completely inappropriate.
My “condensed understanding” of the strengths of the V-model is this:
It defines a set of activities on the left side of the V with associated artefacts aimed at exploring the problem and detailing the solution down to the actual product (the code!). The important part is that these design activities have corresponding activities of verification & validation on the right hand side of the V, in a one-to-one relationship between the design and V&V activity. The number of levels is individual, but usually about 3-5, including code is reasonable.
Where it goes wrong is when the V is laid out in time as a template for progress of a project. This may make sense if you are designing for manufacturing-heavy products, but is useless for software, the time between understanding the problem (top-left part of the V) and where you verify that your understanding is correct is just way too long to be competitive. This is definitely not news for software developers, and is a key point in agile software development (but probably phrased differently).
But it seems to me that in order to optimise the efficiency and speed there is a tendency to downplay the activities above the point of the V ( the working code). Big-upfront-design is seen as such a bad thing that it ends up in no design at all, there is a direct jump between formulating the problem (e.g. user stories) and start coding.
I believe that in an agile project all activities in a V must be executed in each sprint in order to claim to be “truly agile”. Each sprint means a better understanding the problem, a better design to solve it, and a better implementation in the code. Of course all of these are verified and validated. That does not say that these activates are equally large, or the size of the V is the same in alls sprints, but if you leave out the conscious architecture in the sprints you don’t learn to do better in the next sprints.
You should design the activities in the V to provide the maximum added value with respect to the spent effort, which obviously depends on thousands of context-specific factors), but saying they are irrelevant is only reasonable for the simplest of systems, where you have a definition of the problem and code.
Personally I rather define the result of the activities, i.e.the artefacts, and let the teams decide themselves on how to populate them. I know blog readers may cry about excessive documentation, but what I am talking about is the necessity to externalise  information necessary to share between developers, and teams, and to preserve this information over time, something which code never can do.
Long rant, and I’m not even close the exhausting my thoughts on the subject….

Working hours

I am glad I don’t work in the US. This article confirms my personal experience that is is not productive to work long hours and still sustain creativity.

Objectives or activities?

Volvo Cars sets objectives for the company each year. Same as I guess almost every other company. Every department is then required to break down these objectives.
One thing I notice is that often there is confusion between what is an objective and what is the activity to achieve the objective.

Concrete vs. abstract and detail vs. overview...

There often seems to be confusion about two concepts relevant to representing design information, including models.
First there is the scale of abstract versus concrete. Second there is the concept of overview versus details.

If one looks at how a design progresses over time, regardless if one follows a waterfall or agile process, one moves both from abstract to concrete and from overview to details, but they are not the same thing. And I think that agile and waterfall puts different emphasis on on to make these transisions, and where to start and end (topic for another blog post!)


Going from overview to details is simple, the more you know about the problem and the solution the more information is added. think of going from a sketch where you only elaborated on the key classes to understand the system to a class diagam with all classes that are implemented. Using a map as analogy; you increase the scale to see more details, the coastline gets more details, or you see all roads and not only the big ones.

Going from abstract to concrete is also about adding details, and I think that is where the confusion begins. But the details that are added are not of the same type as in the more abstract representation. Here it could be adding all attributes of classes or ports to components. You don't get this information by adding more classes or structure components. In the map analogy it would mean adding indvidual houses on a map which previously only had roads, lakes and forests. It is a new type of information which you cannot deduct (transform) from the more abstract representation.

Testing

I have to admit that I know too little about software testing in practice to be a well-rounded software developer. That does not mean that I am adverse to testing, on the contrary I think that many architecture focus on properties discernible by the end user and not the developers where testers are a key developer role.
So I am curios if there are any patterns on how to design a testable architecture.

I enjoy the blog thoughts from the test eye, which also has a blog roll if you want to explore further test blogs.
I also stumbled across a very good powerpoint summary about testing in industrial settings from Lappeenranta University of Technology.

Quality starts with me

Outside the main dining hall at Volvo Cars R&D headquarters there is some information about ongoing quality work under the heading "Quality starts with me". A quick google search shows this sentence is not something unique to Volvo Cars, but it got me thinking.
To start with: For software (or any product I guess) quality can be seen from to viewpoints:

1. Free from defects
2. Appropriate according to the needs of the user

In many cases one obviously wants to achieve both these objectives, but the actions to reach them vary. Bad case is when one uses an action/method/principle that supports the first objective while believing it is the second one.
Let's say that I review a software specification if all requirements are SMART requirements (insert alternative acronym if desired). Does this support quality of type 1 or 2 above?

When it comes to reviewing or auditing I think it can be applied towards both objectives above, but it requires a lot more of the reviewer if it is the second objective that is the goal of the audit.