Taguchi Methods
for
Achieving Quality
INTRODUCTION

The term Taguchi Methods refers to a collection of principles which make up the framework of a continually evolving approach to quality.

Taguchi’s approach can be broken down into a few different steps. These steps include problem formulation, experimental planning, experimental results and confirmation of the improvement. This is essentially a closed loop process as shown in figure 2. If the objective is not met, the procedure must begin again with modified parameters.

[pic]
Design Process Block Diagram

In Taguchi's approach, optimum design is determined by using design of experiment principles, and consistency of performance is achieved by carrying out the trial conditions under the influence of the noise factors. 1. BRAINSTORMING

This is a necessary first step in any application. The session should include individuals with first hand knowledge of the project. All matters should be decided based on group consensus, (One person -- One vote). - Determine what you are after and how to evaluate it. When there is more than one criterion of evaluation, decide how each criterion is to be weighted and combined for the overall evaluation. - Identify all influencing factors and those to be included in the study. - Determine the factor levels.

- Determine the noise factor and the condition of repetitions. 2. DESIGNING EXPERIMENTS
Using the factors and levels determined in the brainstorming session, the experiments now can be designed and the method carrying them out established. To design the experiment, implement the following: - Select the appropriate orthogonal array. - Assign factor and interaction to columns. - Describe each trial condition. - Decide order and repetitions of trial conditions. 3. ...

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Taguchi Loss Function: Aims to capture the loss to the customer, company and society that can be measured in cost
Taguchi loss function is a diagram of the loss for the company that actual results differ from a target value. Taguchi loss function is intended to capture not only the loss to the customer, but to society and society at large which can be measured by cost. The loss function is not to grasp what cannot be quantified. For that reason the loss of function includes increased pollution as a cost to society. In general, the loss function is shown as a parabola at the point of minimum loss directly above the target value. As she is drawn as a parabola symmetrical in most instances it is not necessarily as the loss function in a real case would be that the actual loss and could be discontinuous and asymmetric. An extremely important concept is the function that displays the weakness of the use of specifications that deal with any outcome between the values that are not rejected as equal. More often while the customer can accept an outcome in the specification they become less satisfied and more likely to find another supplier, as results leave their desired target. This concept has even more value when looking at the loss if it can be measured. While it would be nice to be able to measure all the costs it is often not possible and is worth including known but immeasurable losses in decision-making. And while paying...

...Design of experiments via Taguchimethods: orthogonal arrays
Introduction
The Taguchimethod involves reducing the variation in a process through robust design of experiments. The overall objective of the method is to produce high quality product at low cost to the manufacturer. The Taguchimethod was developed by Dr. Genichi Taguchi of Japan who maintained that variation. Therefore, poor quality in a process affects not only the manufacturer but also society.
He developed a method for designing experiments to investigate how different parameters affect the mean and variance of a process performance characteristic that defines how well the process is functioning. The experimental design proposed by Taguchi involves using orthogonal arrays to organize the parameters affecting the process and the levels at which they should be varied; it allows for the collection of the necessary data to determine which factors most affect product quality with a minimum amount of experimentation, thus saving time and resources. Analysis of variance on the collected data from the Taguchi design of experiments can be used to select new parameter values to optimize the performance characteristic.
In this article, the specific steps involved in the application of the Taguchimethod will be described and...

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TAGUCHI LOSS FUNCTION
EXAMPLE PROBLEMS
1. A blueprint specification for the thickness of a dishwasher part at Partspalace, Inc. is0.325 ± 0.025 centimeters (cm). It costs $10 to scrap a part that is outside thespecifications. Determine the Taguchi loss function for this situation.
2. A team was formed to study the dishwasher part described in Problem 1. Whilecontinuing to work to find the root cause of scrap, they found a way to reduce the scrapcost to $5 per part.
a. Determine the Taguchi loss function for this situation.
b. If the process deviation from target can be held at 0.015 cm, what is the Taguchi loss?
3. An electronic component has a specification of 180 ± 5 ohms. Scrapping the componentresults in an $100 loss.
a. What is the value of k in the Taguchi loss function?
b. If the process is centered on the target specification with a standard deviation of 2
ohms, what is the expected loss per unit?
4. Ruido Unlimited makes electronic soundboards for car stereos. Output voltage to a
certain component on the board must be 15 ± 0.2 volts. Exceeding the limits results in an
estimated loss of $75. Determine the Taguchi loss function.
5. An automatic cookie machine must deposit a specified amount of 15 ± 0.1 grams (g) of
dough for each cookie on a conveyor belt. If the machine either over- or underdeposits themixture, it costs $0.015 to scrap the defective cookie.
a. What...

...is outside the specifications. Determine the Taguchi loss function for this situation.
Answer
7. The Taguchi Loss Function for PlataLimpia, Inc. part is: L(x) = k (x - T)2
$15 = k (0.025)2
k = 24000
L(x) = k (x - T)2 = 24000 (x - T)2
8. A team was formed to study the dishwasher part at PlataLimpia, Inc. described in Problem 7. While continuing to work to find the root cause of scrap, they found a way to reduce the scrap cost to $10 per part.
a. Determine the Taguchi loss function for this situation.
b. If the process deviation from target can be held at 0.015 cm, what is the Taguchi loss?
Answer
8. The Taguchi Loss Function is: L(x) = k (x - T)2
a) $10 = k (0.025)2
k = 16000
L(x) = k (x - T)2 = 16000 (x - T)2
b) L(x) = 16000 (x - T)2
L(0.015) = 16000 (0.015)2 = $3.60
9. A specification for the length of an auto part at PartsDimensions, Inc. is 5.0 ± 0.10 centimeters (cm). It costs $50 to scrap a part that is outside the specifications. Determine the Taguchi loss function for this situation.
Answer
9. The Taguchi Loss Function is: L(x) = k (x - T)2
$50 = k (0.10)2
k = 5000
L(x) = k (x - T)2 = 5000 (x - T)2
10. A team was formed to study the auto part at PartsDimensions described in Problem 9. While continuing to work to find the root cause of scrap, the team found a way to reduce...

...Application of ‘Taguchi Design’ for ‘Reducing serving time of KFC’
Abstract- This case study is showing the application of Taguchi Design for optimizing the servicing time of KFC and to identify the best parameter setting. After observing the processes and understanding the basics, I came out with 3 factors viz. Logistics, Oil Change and Time to Serve. Here I have used L9 Taguchi Design for experimentation with the help of Minitab software at design and analyses phase
Key Words- Factors, Factor Levels, Main Effect Plot for Means, Main Effect Plot for SN Ratio.
Introduction
KFC is a fast food restaurant chain which specializes in fried chicken and is headquartered in Louisville, Kentucky. It was founded in 1930 by Colonel Sanders. It is the second largest restaurant chain (after McDonald’s) with over 18,000 outlets in 120 countries as of December 2012. The company is a subsidiary of Yum! Brands. KFC was one of the first fast food chains to expand internationally, opening outlets in England, Mexico and Jamaica by the mid-1960s. Since then it has expanded globally.
Literature review
Since statistical techniques do not aid continuous quality improvement, the need has arisen to find new techniques and tools to replace the present-day quality systems infected with various statistical techniques. In this context, major portions of the methods...

...be used to justify current practice and make judgment and also to develop theories. Descriptive research design is a scientific method which involves observing and describing the behaviour of a subject without influencing it in any way. It is used to obtain information concerning the current status of the phenomena to describe "what exists" with respect to variables or conditions in a situation. This was based on a cross-sectional data. Cross-sectional data or a cross section of a study population, in statistics and econometrics is a type of one-dimensional data set (Henry, Brady & Johnston, 2008). Cross-sectional data refers to data collected by observing many subjects (such as individuals, firms or countries/regions) at the same point of time, or without regard to differences in time (Henry, et al., 2008). Analysis of cross-sectional data usually consists of comparing the differences among the subjects (Henry, et al., 2008).
Both qualitative and quantitative methods will be used for this study. The study will adopt the quantitative approach which comes from the deductive school of thought. This is because, the study will seek to understand and interpret social interactions concerning workers’ performance appraisal which fall under qualitative research. However, the questionnaire will be coded in order for it to fit into quantitative research methods. The quantitative approach of this research will involve the deployment of...

...Beginning with Science 02: Scientific Investigation
For this assignment you will do two things:
Part I: Evaluate one experimental design. (10 points)
Part II: Design your own experiment using the scientific method. (40 points)
Review each scenario below, and choose one to complete for your assignment. Each scenario contains specific questions that will ask you to provide examples, explain your suggestions for improvement, and refer to the lesson. Be sure to respond to each question in complete sentences.
Part I: Scenarios (select only one)
Scenario 1
Christopher and Kate noticed that after a rainstorm some of the rocks in their yard appear to shrink. They wondered how the mass of the rocks changed when dissolved in water. To determine this, Kate purchased a variety of rocks from a local shop, carefully recording the types of rocks in a data chart. Christopher gathered rocks from the backyard to add to the rocks Kate purchased. They measured each rock's initial mass; then they inserted the rocks one by one into 100 milliliters of water and measured the mass of each rock after it had sat in the water for five minutes. Both Christopher and Kate concluded that store-bought rocks do not dissolve in water. They also concluded that to get rocks that dissolve in water they must be gathered directly from the yard.
1. Describe why the investigation above is not adequate to explain what types of rocks will dissolve in water.
2. Using what...

...Research Methods
Test
1.) Triangulation in a qualitative research study is used to formulate valid and reliable conclusion and can use different methods to search or to gather data. Collecting and comparing information from different aspects can confirm reliability as well as validity. Triangulation in qualitative research not only involves the researcher, but gives peer researchers a chance to view how the study was conducted and interpret it in their own way which can influence the final results. It is important to have others view the way a study was examined, different viewpoints can raise certain questions about a study and if the study was performed in an accurate manner, which leads to more valid results.
2.) A confidence interval signifies a set of particular values, it measures the probability that the population parameter will stay within the set range. Wide and narrow Confidence intervals allow the researchers to see if there is any chance of uncertainty associated with the sample hypothesis and how stable the hypothesis is, also can distinguish who to regard as well as disregard.
3.) Statistical power can detect the probability that the test given will reject the hypothesis if it is false. Statistical power represents the likelihood of saying that there is a relationship, disparity, gain, when one is present. As the power increases or decreases it allows the researcher to detect error. Statistical power is...