follow us:Google+FacebookLinkedInTwitterVimeoRSS Feeds

advertisement

The Whiteboard: Five lessons to learn from General Motors' ignition-switch problem

By

Back to Top Comments Email Print

General Motors, in a series of announcements beginning in February, has recalled 4.8 million cars to replace a faulty ignition switch.

A flaw in the design can allow the switch to inadvertently move from the "on" position to "accessory" or "off," causing power failures that can affect steering, braking and the deployment of airbags. Thirteen people have died in switch-related accidents.

It now appears the company knew about the problem since 2002 and the CEO has been called before Congress. Much can be learned from this.

The company states on its website that the switches can move, "if the torque performance is not to GM specifications." That means that the switch is designed to have a certain range of resistance to rotation and implies that many switches, which did not meet the specifications, still found their way into vehicles and dealer parts inventories.

Lesson one

If your business produces a product or components of a product that can harm people or damage property, make sure you detect and act on safety problems.

Start with a very robust nonconformance process. GM actually knew the switches did not meet its specifications and yet somehow made a decision to go ahead and use them. For items that could affect safety, accepting nonconforming parts "as-is" should require review by multiple departments and perhaps multiple levels of authority.

Set up a safety committee to assess field failures. Staff the committee with experts from design, quality, production and sales. Have the committee review and document all customer failure claims or returns to determine whether they indicate a safety problem.

Give the committee a direct line to the company president, CEO or owner to ensure that its recommendations for design changes or product recalls are highly visible and heard at the top.

Lesson two

Avoid safety problems by identifying failure modes and their possible effects for critical components and systems. Failure mode and effects analysis, or FMEA, has been a widely used design method for decades.

Despite the fancy name, it is actually a quite simple concept that any original equipment manufacturer can implement. You gather experts from design, quality, production and sales to brainstorm the different ways the product could fail and what the effects of each failure would be. Then you assess the probability that failure, or the effects will occur.

A FMEA of the ignition switch would show that one failure mode could be inadvertent rotation to the "off" position. The effect would be shutting off the engine. This would result in significant loss of steering and braking capability in a moving vehicle. If the vehicle hit anything, the airbags might fail to deploy.

The importance of switch torque should not have been a surprise.

Lesson three

Sample inspect critical parts to ensure they meet specification. GM did this one; it just ignored the results and used the switches anyway.

Lesson four

Don't lose design control over an item critical to safety. GM compounded its mistakes when the ignition switch was redesigned. The Wall Street Journal reported that the most recent recall of 971,000 cars is because GM redesigned the switch while using the same part number for the new design as the old one. Because the same part number was used, GM lost track of 95,000 of the defective switches and must recall 971,000 cars that might have the old switch. That is a self-inflicted wound.

Redesigning a defective item, while keeping the same part number, is a fundamental failure of one of the simplest rules of engineering design control. Unfortunately, it is a failure I have seen over and over in companies both large and small.

The simplest test for whether a design change warrants a new part number is commonly called the blind-man rule. If we co-mingle the old and new designs in inventory, and a blind man can reach into the mixed parts and pick one that we will be happy to use, there is no need to change the part number. Clearly, that was not the case here.

Why do so few companies get this right? Because taking out a new part number takes work. Assembly drawings, bills of material and instruction manuals might require revision. The new part must be set up on computer systems. It seems like it will be easier to avoid that and somehow manage the transition to the new design manually.

As GM learned, it isn't that easy. Suddenly, they're wondering where those 95,000 old switches went, and there is no way to know. Now they must recall 971,000 cars because of failure to apply a simple rule.

None of these things are terribly difficult to implement. The simple fact is that many companies just don't pay enough attention to getting all of these activities organized around product safety.

Lesson five

Learn the first four lessons.

Richard Randall is founder and president of management-consulting firm New Level Advisors in Springettsbury Township, York County. Email him at info@newleveladvisors.com.

Write to the Editorial Department at editorial@cpbj.com

advertisement

Comments


Be the first to comment.



Please note: All comments will be reviewed and may take up to 24 hours to appear on the site.

Post Comment
     View Comment Policy
advertisement
  
  
advertisement
  
  
advertisement
Back to Top