The Volkswagen emissions scandal

Great blog post by James Christie on the implications of the Volkswagen emissions scandal for the software testing profession.

What interests me about this is that the defeat device is integral to the control system (ECM); the switch has to operate as part of the normal running of the car. The software is constantly checking the car’s behaviour to establish whether it is taking part in a federal emissions test or just running about normally. The testing of this switch would therefore have been part of the testing of the ECM. There’s no question of some separate piece of kit or software over-riding the ECM.

This means the software testers were presumably complicit in the conspiracy. If they were not complicit then that would mean that they were unaware of the existence of the different dyno and road calibrations of the ECM. They would have been so isolated from the development and the functionality of the ECM that they couldn’t have been performing any responsible, professional testing at all.

I’ve always maintained that a good tester needs to be able to speak truth to power, and any tester who simply says whatever the project manager wants to hear is not a worthwhile tester. But Christie follows that to its obvious conclusion, and raises some very important questions on the testing profession’s moral and ethical responsibilities. This is something the testing community doesn’t talk enough about.

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2 Responses to The Volkswagen emissions scandal

  1. John P. says:

    My guess is that at some point in the past it was considered expedient by someone at VW to get this functionality built into a software module. Maybe to meet some deadline like a release date. Maybe they even intended to fix it later on. But then the people involved moved on to other jobs and it was no longer their problem any more. But no-one who was left knew that there was a problem and the software module got reused in later versions without anyone realising the implications it held. After all, it had been signed off originally and hadn’t been changed so there was no reason to question it. Like Google collecting wi-fi data with their StreetView cars because someone used a module that did something they didn’t realise happened.

    So if the testers didn’t know that the “feature” was there then they wouldn’t have tested it and it’s unlikely they would have tripped over it – given that it is apparently designed to only kick in during a very specific set of circumstances (e.g. going at test speed, no input from the steering wheel, certain pressures in the system and so on). In fact, the engine was probably tested in isolation. So the only people who would have noticed the good performance would be the technicians getting the stats for the finished car who would have attributed it to good overall engineering rather than cheating software.

    Really, apparently this thing has been there for years and no-one has noticed it until now so it must be pretty well hidden. None of the regulatory testers saw it, nor the techs who service & maintain them, nor the people who mess with the ECM to get better performance from the cars. I bet car companies take their rivals cars apart to study them and they didn’t see it either – or maybe they did and kept quiet because “there but for the grace of God go I”. But even then it would have leaked before now as one company tried to gain advantage by smearing another.

    I’m not saying all this is excusable, but I can understand how this sort of thing happens because plain old human nature means that we take the easy route. As a race we are fundamentally lazy and we keep falling over ourselves because of it. Always were, always will be.

  2. Michael says:

    I’m looking forward to the results of the enquiry into this.
    My guess is that there will be a chain of events with unintended consequences.
    However someone must have seen what was going on. Did that peron report it?
    If not then we know where the ton of bricks needs to fall.
    If there was a report then someone suppressed it. That someone becomes the target.