Archives For Toyota

Technical debt

05/09/2015 — 1 Comment

St Briavels Castle Debtors Prison (Image source: Public domain)

Paying down the debt

A great term that I’ve just come across, technical debt is a metaphor coined by Ward Cunningham to reflect on how a decision to act expediently for an immediate reason may have longer term consequences. This is a classic problem during design and development where we have to balance various ‘quality’ factors against cost and schedule. The point of the metaphor is that this debt doesn’t go away, the interest on that sloppy or expedient design solution keeps on getting paid every time you make a change and find that it’s harder than it should be. Turning around and ‘fixing’ the design in effect pays back the principal that you originally incurred. Failing to pay off the principal? Well such tales can end darkly. Continue Reading…

Toyota ECM (Image source: Barr testimony presentation)

Comparing and contrasting

In 2010 NASA was called in by the National Highway Transport Safety Administration to help in figuring out the reason for reported unintended Toyota Camry accelerations. They subsequently published a report including a dedicated software annex. What’s interesting to me is the different outcome and conclusions of the two reports regarding software.  Continue Reading…

Waaay back in 2002 Chris Holloway wrote a paper that used a fictional civil court case involving the hazardous failure of software to show that much of the expertise and received wisdom of software engineering was, using the standards of the US federal judiciary, junky and at best opinion based.

Rereading the transcripts of Phillip Koopman, and Michael Barr in the 2013 Toyota spaghetti monster case I am struck both by how little things have changed and how far actual state of the industry can be from state of the practice, let alone state of the art. Life recapitulates art I guess, though not in a good way.

Toyota ECM (Image source: Barr testimony presentation)Economy of mechanism and fail safe defaults

I’ve just finished reading the testimony of Phil Koopman and Michael Barr given for the Toyota un-commanded acceleration lawsuit. Toyota settled after they were found guilty of acting with reckless disregard, but before the jury came back with their decision on punitive damages, and I’m not surprised.

Continue Reading…

A slightly disturbing story of the car manufacturer, it’s software and what happened when that software failed… or at least was presumed to fail.