AUTOSAR webinar 2009-11-03

Vector hosts a webinar on the basics of ECU development with AUTOSAR on 24 November 10:00 EST. You can register for the webinar here.

Sorry for the shameless plug for a commercial company, but at least this seems to be free. And there are few opportunities to learn more about AUTOSAR that is not hosted by a tool vendor or supplier...

"The Concise Handbook of Real-Time Systems" 2009-10-28

Very long ago (1999?) I attended a conference where I got a small booklet called "The Concise Handbook of Real-Time Systems" by TimeSys Corporation.
I found the booklet to be a very usefull distillation of the most important concepts when designing real-time software. I even ordered some more copies for interested collegues. I hope more developers will be familliar with the content, it would prevent a number of problems...

I don't think the booklet can be ordered any more from the original company, but a quick googling found a later version in PDF here.

Lack of process view of automotive software 2009-10-26

When discussing an architectural problem with my colleagues we identified that an initialisation/activation mechanism could be defined either as a method used between logical components or as an initialisation between run-time processes. But we could not propose the second mechanism since it would be impossible to communicate to the developers.

The reason for this is that we are not using a process view at Volvo (or at any other OEM that I have worked with either). With process view I mean the view as defined in the 4+1 paper by P. Kruchten. And I have not seen any other viewpoint used here that would fulfil a similar purpose.
This has some interesting implications:

• The deployment of functionality is in Kruchten's paper done by assigning logical components to processes and the deploying the processes onto the physical view. Among OEMs the deployment relationship is directly between static logical components and the hardware (i.e. ECUs). So there is no possibility to express concepts as "concurrency", "precedes" or "is activated by".
• It must be the responsibility of the ECU suppliers to define the process view of their ECU. And to be honest I have no idea if they do since this is not requested nor followed up by OEMs...
• The fundamental building block in AUTOSAR is the software component (SW-C), which can be called a static logical component if one is not too much of perfectionist with meta-models. The SW-C contains runnable entities which is the entity that is scheduled. But also in AUTOSAR it is the SW-C and not the runnable entities that are deployed to ECUs. I think this is driven by the first item above...
• Since it is the static SW-C that has the explicit relationship to other ECUs through the defined port and interface mechanisms in AUTOSAR there is no possibility to define a "dynamic" mechanism to "activate", "run simultaneously" or something similar usually defined in a process view (or process architecture).

I was thinking of writing a short paper elaborating on this and relating it to some research papers, but I probably will not. First it is not directly in line with the subject of my thesis. Second there are more pressing things to do. So if anybody else wants to pursue this I would be glad to be a co-author, discussion partner ot at least get mentioned in the acknowledgements.

The significant benefit of software architecture? 2009-10-20

I have been convinced that it is impossible to design a perfect architecture. This is supported by a quote by P Kruchten which I have already mentioned in my blog:

The life of a software architect is a long (and sometimes painful) succession of suboptimal decisions made partly in the dark.

One corollary conclusion I make from this is:

The significant benefit of a software architecture is that it exists, not that it optimally fulfills the prerequisistes.

If the purpose of an architecture is to guide and control subsequent developement the fact that it actually provides some guidance is more important than the guidance have exactly the right bearing. I have a gut feeling that this is intimately related to if the system has any conceptual integrity or not.

Could I write some kind of position paper on this? What arguments could I use? Is such a paper already published?

Project presentation 2009-10-16

I gave a presentation of my project at the annual Volvo Industrial PhD conference:

I did get the question how my project would have looked like if I would have had a quantitative approach instead. I wished I had the Dilbert strip about numbers as a backup-slide.
Now I had to resort to a serious answer that for some research a qualitative approach will get you a better understanding than a quantitative...