Taguchi methods

UNIVERSIDAD JUÁREZ AUTÓNOMA DE TABASCO
DIVISIÓN ACADÉMICA DE CIENCIAS ECONÓMICAS ADMINISTRATIVAS
COORDINACIÓN DE INVESTIGACIÓN Y ESTUDIOS DE POSTGRADO
JEFATURA DE ESTUDIO DE POSTGRADOMAESTRÍA EN ADMINISTRACIÓNAsignatura: CALIDAD Y COMPETITIVIDADTópico:TAGUCHI METHODSExpositor:Juan Manuel Zaragoza RomeroFacilitador:M.A. M.I. Fabio García MartínezVillahermosa, Tabasco Mayo-Agosto 2011 |TAGUCHI METHODS

BACKGROUND & OVERVIEW OF TAGUCHI METHODS
After the Second World War, the allied forces found that the quality of the Japanese telephone system was extremely poor and totally unsuitable for longterm communication purposes. To improve the system the allied command recommended establishing research facilities in order to develop a state-of-the-art communication system. The Japanesefounded the Electrical Communication Laboratories (ECL) with Dr. Genichi Taguchi in charge of improving the R&D productivity and enhancing product quality. He observed that a great deal of time and money was expended on engineering experimentation and testing (Ranjit 1990). Little emphasis was given to the process of creative brainstorming to minimise the expenditure of resources. He noticedthat poor quality cannot be improved by the process of inspection, screening and salvaging. No amount of inspection can put quality back into the product. Therefore, he believed that quality concepts should be based upon, and developed around, the philosophy of prevention.
Taguchi started to develop new methods to optimise the process of engineering experimentation. He believed that the best wayto improve quality was to design and build it into the product. He developed the techniques which are now known as Taguchi Methods. His main contribution lies not in the mathematical formulation of the design of experiments, but rather in the accompanying philosophy. His concepts produced a unique and powerful quality improvement technique that differs from traditional practices. He developedmanufacturing systems that were “robust” or insensitive to daily and seasonal variations of environment, machine wear and other external factors.
His philosophy had far reaching consequences, yet it is founded on three very simple concepts. His techniques arise entirely out of these three ideas.
The concepts are:
1. Quality should be designed into the product and not inspected into it.
2. Qualityis better achieved by minimising the deviation from a target. The product should be so designed that it is immune to uncontrollable environmental factors.
3. The cost quality should be measured as a function of deviation from the standard and the losses should be measured system-wide.
Taguchi viewed quality improvement as an ongoing effort. He continually strived to reduce the variation aroundthe target value. The first step towards improving quality is to achieve the population distribution as close to the target value as possible. To accomplish this, Taguchi designed experiments using especially constructed tables known as “Orthogonal Arrays” (OA). The use of these tables makes the design of experiments very easy and consistent.
The Taguchi Method is applied in four steps.
1.Brainstorm the quality characteristics and design parameters important to the product/process.
2. Design and conduct the experiments.
3. Analyse the results to determine the optimum conditions.
4. Run a confirmatory test using the optimum conditions.

TAGUCHI'S DEFINITION OF QUALITY
The old traditional definition of quality states quality is conformance to specifications. This definition wasexpanded by Joseph M. Juran (1904-) in 1974 and then by the American Society for Quality Control (ASQC) in 1983. Juran observed that "quality is fitness for use." The ASQC defined quality as" the totality of features and characteristics of a product or service that bear on its ability to satisfy given needs."
Taguchi presented another definition of quality. His definition stressed the losses...