Quality Guru Analysis

Genichi TaguchiQUALITY GURU ANALYSISSamapriya BanerjeeRahul KumarRasika Iyer1Genichi Taguchi was anengineerandstatistician, whothe 1950s onwards, Taguchi developed a methodology for applyingstatisticsto improve the quality of manufactured goods.

Dr. Taguchi's philosophy began taking shape in the early 1950s when he was recruited to help correct postwar Japan's crippled telephone system.Who was Taguchi?

2In 1950, he joined the Electrical Communications Laboratory (ECL) of the Nippon Telegraph and Telephone Corporation just as statistical quality control was beginning to become popular in Japan.

Under the influence of W. Edwards Deming and the Japanese Union of Scientists and Engineers. ECL was engaged in a rivalry with Bell Labs to develop cross bar and telephone switching systems, and Taguchi spent his twelve years there in developing methods for enhancing quality and reliability. Even at this point, he was beginning to consult widely in Japanese industry, with Toyota being an early adopter of his ideas.

During the 1950s, he collaborated widely and in 1954-1955 was visiting professor at the Indian Statistical Institute, where he worked with C. R. Rao, Ronald Fisher and Walter A. Shewhart.While working at the SQC Unit of ISI, he was introduced to the orthogonal arrays invented by C. R. Rao - a topic which was to be instrumental in enabling him to develop the foundation blocks of what is now known as Taguchi methods.Key elements of his quality philosophy include the following:Taguchi loss function;The philosophy of off-line quality controlInnovations in the statistical design of experiments, notably the use of an outer array for factors that are uncontrollable in real life, but are systematically varied in the experiment.

Taguchi devised an equation to quantify the decline of a customer's perceived value of a product as its quality declines. Essentially, it tells managers how much revenue they are losing because of variability in their production process. It is a powerful tool for projecting the benefits of a quality improvement program. Taguchi was the first person to equate quality with cost.The Loss FunctionThe Loss Function is graphical depiction of loss to describe a phenomenon affecting the value of products produced by a company. It made clear the concept that quality does not suddenly plummet when, for instance, a machinist exceeds a rigid blueprint tolerance.

Instead "loss" in value progressively increases as variation increases from the intended condition. This was considered a breakthrough in describing quality, and helped fuel the continuous improvement movement that since has become known as lean manufacturing.

When evaluating a production process analysis will undoubtedly identify outside factors or noise which cause deviations from the mean. Isolating these factors to determine their individual effects can be a very costly and time consuming process. Taguchi devised a way to use orthogonal arrays to isolate these noise factors from all others in a cost effective manner.Orthogonal Arrays and Linear Graphs

Some noise factors can be identified, isolated and even eliminated but others cannot. For instance it is too difficult to predict and prepare for any possible weather condition. Taguchi therefore referred to the ability of a process or product to work as intended regardless of uncontrollable outside influences as robustness. He was pivotal in many companies' development of products and processes which perform uniformly regardless of uncontrollable forces; an obviously beneficial service.RobustnessIt is a system of cost-driven quality engineering that emphasizes the effective application of engineering strategies rather than advanced statistical techniques.

It includes both upstream and shop-floor quality engineering.Upstream methods efficiently use small-scale experiments to reduce variability and find cost-effective, robust designs for large-scale production and the marketplace.Shop-floor techniques provide cost-based, real-time methods for monitoring and maintaining quality in production.

The Taguchi Methods

In general, the farther upstream a quality method is applied, the greater leverage it produces on the improvement, and the more it reduces the cost and time. Most typical applications of Taguchi Methods thus far have centered around two main areas:Improving an existing productImproving a process for a specific product

Systematic and widespread application of Dr. Taguchi's straightforward product development philosophy, as well as his comprehensive set of design decision-making tools, has contributed significantly to Japanese industry's prowess in producing world class, low cost, quality products rapidly. In 1982, the American Supplier Institute introduced Dr. Taguchi and his methods to the U.S. market. Since that time, companies that have adopted his techniques and philosophy have collectively saved hundreds of millions of dollars worldwide.AT&T Bell Laboratories(Computer Response-Time Optimization Using Orthogonal Array Experiments)The objective was to reduce a computer system's response time under a specified range of load and environmental conditions. This was achieved by simultaneously studying a large number of system parameters, as opposed to studying one parameter at a time. The resulting optimum system configuration gave a 60% reduction in mean response time.

Ford Motor Company(Fuel Pump Flow)The variability range in fuel pump flow was reduced by 65%. Development of a new fuel pump with severe requirements was completed eight months prior to plan as a result of this study.Success StoriesXerox(Copy machine paper arrival time)Xerox reduced the variability in arrival time and paper orientation by 66%. Xerox is probably the most advanced user of Taguchi Methods in the U.S. They started implementation of Robust Design in 1982, and today the Robust Design approach is fully integrated into their product development process.

Nissan Motor(Brake Pad Study)Using dynamic characteristics, Nissan improved the efficiency of the energy transformation to the brake pad. Overall weight of the brake system was reduced and squeal rate was reduced to 4% of the original condition. Nissan Technical Center conducts 70 projects annually, all using dynamic characteristics.

CDI/3M Healthcare(Oxygen Sensor Variability Reduction)The variability of measured value from an oxygen sensor used for open heart surgery was reduced by 70%. In addition (using a double-signal approach), a robust function was developed to compensate for changes in blood temperature.

"Some describe [robust engineering] as just plain good engineering and not all that joltingly new. Others view it as merely another fad. Using robust methods saved time and money in developing Saturn's manual and automatic transmissions, and also produced about 30 new patents."Robert C. Downs,Chief Engineer-transmissions at GM's Saturn subsidiary

"...the early, methodical application of Quality Engineering [robust design]`best practices' within a disciplined product development process will yield improved reliability along with many other economic and quality related benefits."Skip Creveling,Eastman Kodak Company

"The auto industry isn't alone in using robust engineering procedures. The philosophy has its converts in diverse industries such as aerospace, appliance manufacturing, and electronics. Proponents have developed mathematical formulas for measuring the "robustness" of individual designs and report cases of dramatic improvements when robust engineering guidelines have been applied to specific problems."(WARD'S Auto World - March 1994)

Dr. Taguchi has been awarded the coveted Deming Prize on three separate occasions for his contributions to the field of Quality Engineering.

In 1986, he received the Willard F. Rockwell Medal for combining engineering and statistical methods to achieve rapid improvements in cost and quality by optimizing product design and manufacturing processes.

He received the Blue Ribbon Award from the Emperor of Japan in 1990 for his contribution to industry.Awards and RecognitionSystematic and widespread application of Dr. Taguchi's straightforward product development philosophy, as well as his comprehensive set of design decision-making tools, has contributed significantly to Japanese industry's prowess in producing world class, low cost, quality products rapidly. In 1982, the American Supplier Institute introduced Dr. Taguchi and his methods to the U.S. market. Since that time, companies that have adopted his techniques and philosophy have collectively saved hundreds of millions of dollars worldwide.Conclusion

After WWII Japanese manufacturers were struggling to survive with very limited resources. If it were not for the advancements of Taguchi the country might not have stayed afloat let alone flourish as it has. Taguchi revolutionized the manufacturing process in Japan through cost savings. He understood, like many other engineers, that all manufacturing processes are affected by outside influences, noise. However, Taguchi realized methods of identifying those noise sources which have the greatest effects on product variability. His ideas have been adopted by successful manufacturers around the globe because of their results in creating superior production processes at much lower costs.The othergreaterEFFECThttp://www.amsup.com/www.qualitygurus.comWadsworth, Harrison M. (1997).Handbook of statistical methods for engineers and scientists(2nd ed.). New York: McGraw-Hill Professional.Taguchi, Genichi (June 1995). "Quality engineering (Taguchi methods) for the development of electronic circuit technologyhttp://www.asq.org/ReferencesTHANK YOU