Ford Motor Company: driving down defect rates

by Minitab Limited on 15th August 2007

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Minitab

When you pick up your new vehicle at the dealership, you expect it to be free of exterior finish defects. Farzin Ghodsi, Black Belt at Ford Worldwide Direct Market Operations’ Consumer Driven 6-Sigma initiative, says, The goal at Ford is to present customers with a vehicle with a ‘Factory Fresh Look’ no matter where in the world they are located.

It's a huge undertaking to deliver defect-free vehicles after they have been transported thousands of miles by truck, rail, and ocean carrier to dealerships around the world. When the people at Ford saw that exported vehicles arrived at their final destination point with exterior surface defects, they knew they had to take action. The cost of repairs and the negative impact on customer satisfaction levels drove the company to search for a solution to the problem.

At the manufacturing plants, vehicles destined for export had transit protection film applied to horizontal surfaces. Transit protection film is a plastic sheet with adhesive on one side and a chemical-resistant material on the other side, designed to protect the vehicle's exterior on the journey from the plant to the US port and then throughout the ocean voyage to the distributor.

During transport, large portions of the transit film lifted away from the vehicle surface and damage occurred. Dirt and debris would become trapped between the loose film and the vehicle's finish, and the film would lash against the fresh paint and cause defects.

When the vehicles arrived at the port, the port processors had only a few options before loading the vehicles on the ocean-bound transport vessels:

Wash the car (which often removed even more of the film).
Take no action and chance that more damage would occur to the vehicle before arrival at the final destination.
Repair the film although the cost of fixing the material was often more costly than the original application.

In June 2001, a Customer Driven 6-Sigma project team was selected to reduce exterior
finish defects caused by the transit protection film on exported vehicles.

The team chose two target test locations and one destination market: a Ford manufacturing facility in St. Thomas, Canada; their port processing facility in Delaware; and one destination market - the Middle East region. Farzin Ghodsi, Black Belt and project leader, explained the decision, 'We selected this market for our project because we knew that the extreme temperatures and difficult ocean transport conditions that our vehicles were exposed to during the journey would be a test for our processes. We knew that if we could reduce the defects under these extreme conditions, that our improvements would be robust enough to create positive results in less challenging environments.'

The team developed a high-level process map of the vehicle transit process and followed Grand Marquis and Crown Victoria models from St.Thomas to the port in Delaware. Using data on film-induced defects from 2000-2001, the team produced a cause-and-effect diagram (fishbone analysis) to capture, categorize, and prioritize potential root causes of transit film- induced defects.

The team examined the processes within production areas for potential causes of failure. At the plant level, they looked at many factors including transit film installation instructions, differences among operators and shifts, proper training of operators, type of transit film material used, and surface cleaning methods.

At the plant level, several key variables were identified that influenced the defect rate, including:

Transit film material they identified that flexibility, adhesion, and re-adhesion properties were important.

Operator training and supervision.

By using Design of Experiments (DOE) the team were able to screen the factors to determine which were critical for explaining process variation. The team used MINITAB to understand how the factors interact and to identify areas for intervention and process improvement opportunities.

Ford compared defect rates for:

Vehicles covered with existing transit protection film.

Vehicles covered with a new protection film.

Vehicles without protection film.

The data showed that the new material reduced transit film induced defects from 289%(2.89 defects per vehicle) to 129%, as compared to the existing material. Use of the new material also resulted in a significant cost savings since the new material was less expensive.