Whenever I write about continuous improvement and lean Six Sigma, without fail I get a comment about Toyota and its quality issues. So I decided to investigate this matter further, present the facts, and let the data be the voice of reason. I do expect the proverbial “Yabut and Costello” comments—i.e., “But what about this and what about that?” My goal, though, is to compare trends over time and across the automotive industry.
In summary, when compared to the other automobile manufacturers, Toyota’s quality issues are far less severe than what we are lead to believe. However, from a lean Six Sigma perspective, there is much work to be done, and here are the data to demonstrate this.
We will start by looking at a comprehensive survey conducted in 2011, called the “Initial Quality Study” (IQS). The IQS looks at the problems owners have reported during the first 90 days of owning a car. Participants of the study were asked to select from 228 potential problems with their vehicles, from major malfunction to problems understanding controls. The results of that study are presented in the graph below. The values for it were obtained here.
Source: 2011 Initial Quality Study 2011
The graph shows the problems per 100 vehicles for the top 10 vehicles, i.e., those with the fewest problems per 100 vehicles. A problem may include problems in assembly or design, even if the design was built according to specifications. According to the graph and the 2011 IQS survey, out of the top 10 brands with the least problems per 100 vehicles, Lexus had 73 problems per 100 vehicles while GMC had 103. Not shown in the graph but interesting is that Ford had the seventh highest number of problems per 100 vehicles at 117.
Toyota, although not faring the best, does have one of the best records with respect to problems per 100 vehicles among more than 20 vehicles included in the 2011 IQS survey.
In the 2012 IQS survey, for a second year in row Lexus ranked as the best car with respect to the lowest number of problems per 100 vehicles—73 problems per 100 vehicles. In addition, Honda was once again ranked among the top five with respect to the lowest number of problems per 100 vehicles.
Jaguar, Porsche, Cadillac, Honda, and Infinity had substantial improvements in the number of problems per 100 vehicles (20% to 50% improvement). Note that a positive percentage increase means an improvement, i.e., the number of problems per 100 vehicles declined.
For Toyota, the problems per 100 vehicles stays within the top 10, and the improvement from the year before is 12 percent, which is much higher than the industry average improvement of 5 percent.
Although more years of data would be required to see for certain if the quality trends observed in 2011 and 2012 are likely to continue, for now Toyota does seem to have better-than-average quality ratings relative to the overall automobile industry.
That being said, from a lean Six Sigma perspective, 88 defects per 100 vehicles is less than desirable. The goal for Six Sigma is 3.4 defects per million, which is drastically different than what Toyota is achieving today. In other words, Toyota has much room to improve on its quality relative to the lean Six Sigma standards.
Perhaps it is time for Toyota and other car manufactures to focus more on Six Sigma (i.e., focus on quality) and less on lean (i.e., focus on time). What do you think?
This article first appeared on the Toppazzini and Lee Consulting website and is used with permission.