Toyota’s ‘Devil’s Advocate’ Policy Looks to Restore Quality

2 Feb 2011 Sandeep Mehta

We have talked about Toyota recalls and the announcement by Mr. Todyoda to fix the problems.  You might recall that Mr. Toyoda’s solution to reducing errors was to increase quality control.  Well, Toyota has followed through.  The article Toyota’s ‘Devil’s Advocate’ Policy Looks to Restore Quality provides some details.

 The ‘devil’s advocate’ approach to vehicle design is a key element of the new Toyota. Under the plan, the company gives engineers four extra weeks to tear down and evaluate new vehicles.

The goal is to use the car in ways the owner’s manual doesn’t even consider.  That’s because Toyota found out the hard way last year that customers use cars in unpredictable ways. It traced some unintended acceleration cases to gas pedals being jammed by stacked floor mats — an ill-advised practice for which Toyota engineers didn’t plan.

Interesting! So, if the customers use the car in an unpredictable way, why think of it AFTER the design is complete? Also, if the use is unpredictable, how can you account for it? If it can be predicted, why not change design objectives to address those use cases?  You might have guessed it: I do not believe this way of implementing a devil’s advocate process will do much to mitigate risks of recall.

But not everyone agrees Toyota has solved the problems that led to last year’s crisis. One skeptic is Mr. Ditlow of the Center for Auto Safety. He said Toyota’s new approach to dealing with complaints of quality glitches such as unintended acceleration still is “pretty much the same-old, same-old.”

What is needed is a new process to manage automotive R&D.  You might also recall that the root cause of the recalls was NOT poor quality control, but a large increase in complexity or vehicles being developed. I believe that adding extra quality control steps at the END of development does little to address the complexity.  Here is what I suggest:

  • Make sure the system objectives are defined correctly.  Use the devil’s advocates in helping balance and guide objectives.
  • Link objectives to detailed requirements across the entire system hierarchy
  • Link requirements to risks of failure.  That is, perform concurrent risk assessment and integrate quality control in the design process.  
  • Integrate devil’s advocates in the risk assessment process and fix it while there is time!

If you don’t do this, you run into many problems.  The so-called Toyota Devil’s Advocate quality control process did this :

Toyota and the supplier switched to crisis mode. They designed a new pinchless wiper and the Yaris still made the scheduled start of production in November.
“We really had to push hard,” recalled Katsutoshi Sakata, Toyota Motor Corp.’s lead executive for quality research and development. “But there’s a new mindset here that we will address even the smallest of issues.”

We can surely do better.

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