The Taguchi Method:The Taguchi Method:

THE SERVICE MANAGER’S PRIMER TO QUALITYTHE SERVICE MANAGER’S PRIMER TO QUALITY

Submitted to:- Submitted by:-Submitted to:- Submitted by:-Mr. Pawan Kamboj Sir Chetan GosainMr. Pawan Kamboj Sir Chetan Gosain

(Lect. In Mechanical Department(Lect. In Mechanical Department) ) Roll No:-10512 Roll No:-10512 Mech. Branch Mech. Branch

44thth Year/8 Year/8thth Sem Sem

C.D.L.M Govt. Engg. College

GENICHI TAGUCHIGENICHI TAGUCHI

• Born in Japan, 1924Born in Japan, 1924

• Electrical EngineerElectrical Engineer

• Worked during 1950’s to improve Worked during 1950’s to improve Japan’s post-WWII telephone Japan’s post-WWII telephone communication systemcommunication system

• Father of the “Taguchi Method” and Father of the “Taguchi Method” and “Robust Engineering”“Robust Engineering”

Topics CoveredTopics Covered

Dr. Dr. GenichiGenichi Taguchi Taguchi

The Taguchi The Taguchi MethodMethod

--Quality Loss FunctionQuality Loss Function

The Taguchi methodThe Taguchi method

•QualityQuality•Robust DesignRobust Design•Quality Loss FunctionQuality Loss Function

Don’t run away!Don’t run away!

• Not a mathematician? Not a mathematician?

• You can still successfully apply Taguchi You can still successfully apply Taguchi Method concepts to your service Method concepts to your service business.business.

• Basic concepts are simple.Basic concepts are simple.

• Just keep reading.Just keep reading.

Competitive Edge 101:Competitive Edge 101:

• ““In the next century, the capability of In the next century, the capability of developing robust technology will be developing robust technology will be essential to the competitiveness of any essential to the competitiveness of any manufacturing enterprise.” (Tsai) manufacturing enterprise.” (Tsai) (Taguchi: p (Taguchi: p xi)xi)

Competitive Edge 102:Competitive Edge 102:

• ““To compete successfully in the To compete successfully in the global marketplace, organizations global marketplace, organizations must have the ability to produce a must have the ability to produce a variety of high-quality, low-cost variety of high-quality, low-cost products that fully satisfy products that fully satisfy customers’ needs.” customers’ needs.” (Robust Engineering; p. xiii)(Robust Engineering; p. xiii)

Quality DefinedQuality Defined

• Ideal QualityIdeal Quality- - reference pointreference point ( (target valuetarget value) )

for determining the quality level of for determining the quality level of a product or service.a product or service.

- delivery of a product or a service - delivery of a product or a service that reliably performs it’s intended that reliably performs it’s intended use throughout it’s life cycle under use throughout it’s life cycle under reasonable conditions.reasonable conditions.

Robust DesignRobust Design

• ““An Engineering methodology for An Engineering methodology for improving productivity during research improving productivity during research and development so that high-quality and development so that high-quality products can be produced quickly and products can be produced quickly and at low cost” at low cost” (1).(1).

• Products and services designed defect Products and services designed defect free and of high qualityfree and of high quality

• A design with minimum sensitivity to A design with minimum sensitivity to variations in uncontrollable factors.variations in uncontrollable factors.

Quality Loss Quality Loss FunctionFunction

• DefinedDefined

-economical and societal penalties -economical and societal penalties incurred as a result of purchasing a incurred as a result of purchasing a nonconforming product.nonconforming product.

DeterminingDeterminingQuality Loss FunctionQuality Loss Function

•Specifications are setSpecifications are set•Specify a target with Specify a target with

minimal variationminimal variation•Increase in variation Increase in variation

cause loss to societycause loss to society

Set SpecificationsSet Specifications

•Loss to societyLoss to society-Product rejection-Product rejection-Product rework-Product rework-Pollution-Pollution

Specify a target withSpecify a target with minimal variationminimal variation

Specify a target withSpecify a target with minimal variationminimal variation

• Disagreements with standard Disagreements with standard qualityquality

LSL- Lower specification limitLSL- Lower specification limit

USL- Upper specification limitUSL- Upper specification limit

Specify a target withSpecify a target with minimal variationminimal variation

• Quadratic Loss FunctionQuadratic Loss Function

Why use Taguichi’s Why use Taguichi’s Quality Loss Function?Quality Loss Function?

1) To find out how much loss is 1) To find out how much loss is brought to Society due to a brought to Society due to a purchase of a nonconforming purchase of a nonconforming product.product.

2) To implement a product design 2) To implement a product design improvement. improvement.

How can we use Taguchi’s How can we use Taguchi’s QualityQuality Loss Function in real life?Loss Function in real life?

Let’s assume that you are an Operations Manager at a Let’s assume that you are an Operations Manager at a company that produces custom made doors and door company that produces custom made doors and door frames. During the winter, due to cold weather, doors frames. During the winter, due to cold weather, doors tend to shrink which lets in cold air through the cracks tend to shrink which lets in cold air through the cracks between the door and the door frame. During the between the door and the door frame. During the summer doors tend to expand beyond it’s normal size summer doors tend to expand beyond it’s normal size due to hot weather, which makes to door hard to open due to hot weather, which makes to door hard to open because it rubs against the door frame. Your job is to because it rubs against the door frame. Your job is to produce a door, where dimensions (length and width of produce a door, where dimensions (length and width of the door) are set to a specific target level. In other the door) are set to a specific target level. In other words in the Winter the door cannot let any cold air in words in the Winter the door cannot let any cold air in the house and it should open properly in the Summer.the house and it should open properly in the Summer.

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How can we use Taguchi’s How can we use Taguchi’s Quality Loss Function in real life?Quality Loss Function in real life?

The picture shows the same kind of a door under different weather conditions. The way to set a target at a specific level, we must first calculate the dimensions of the door under cold conditions and then during the hot conditions (compared to conditions during the winter and the summer). We then take the most cold temp. and add it to the most hot temp.. We then take the answer and divide it by two to get the average temp. We then place the door under the average temp. to find our set dimensions. These dimensions should be the best solution to a robust design.

How can we use Taguchi’s Quality Loss Function in real life?

Basic Ideas:Basic Ideas:• CUSTOMER SATISFACTIONCUSTOMER SATISFACTION

• Design to the highest standards early Design to the highest standards early in the process to eliminate all non-in the process to eliminate all non-random errorsrandom errors

• Quality Loss = Loss to Society Quality Loss = Loss to Society quantified through “Quality Loss quantified through “Quality Loss Function”Function”

• Variation (+/-) from optimal measure Variation (+/-) from optimal measure results in a loss.results in a loss.

Customer SatisfactionCustomer Satisfaction

• Ways to measure service:Ways to measure service:

1. Returning customers1. Returning customers

2. Number of complaints (1:10)2. Number of complaints (1:10)

3. Number of compliments3. Number of compliments

4. Employee attitude4. Employee attitude

Quality Loss ConceptQuality Loss Concept

• Deviation from Deviation from target results in target results in loss.loss.– Lower than targetLower than target

– Greater than Greater than targettarget

– Both loseBoth lose

Quality Loss FunctionQuality Loss Function

• Quantify the LossQuantify the Loss

• Warning: Warning:

Next slide contains Next slide contains math formulasmath formulas

• But give it a try!But give it a try!

Quality Loss Function IIQuality Loss Function II

LL((yy) = ) = kk((yy--mm))22

L(yL(y) = Loss) = Loss

kk = constant = = constant = cost to correctcost to correct

tolerancetolerance22

yy = reported value = reported value

mm = mean value (average) = mean value (average)(Taguchi On Robust Technology p. 22)(Taguchi On Robust Technology p. 22)

Example:Example:

• Company C received an average of 10 Company C received an average of 10 complaints per month last year. In November complaints per month last year. In November they received 15 complaints (y). Management they received 15 complaints (y). Management sets an acceptable level at 2 (tolerance).sets an acceptable level at 2 (tolerance).

• It costs the company $50 directly per It costs the company $50 directly per complaint to correct the problems. They complaint to correct the problems. They determined the cost in lost sales to be $100.determined the cost in lost sales to be $100.

• Total cost per complaint: $150Total cost per complaint: $150

Example continued:Example continued:

kk = $150/2 = $150/22 = 2 = $37.50$37.50

L(y) L(y) = = 37.50 (15-10)37.50 (15-10)22

= 37.50 (5)= 37.50 (5)22

= 37.50 (25)= 37.50 (25)

= $937.50 is loss for the = $937.50 is loss for the month of Novembermonth of November

MATH DONE!MATH DONE!

Taguchi Experiment – Steps Taguchi Experiment – Steps

According to Dr. Foster:According to Dr. Foster: (OM Review p. 38-44)(OM Review p. 38-44)

• Managers’ job:Managers’ job:– Identify the ProblemsIdentify the Problems– BrainstormBrainstorm– Contribute to experiment designContribute to experiment design

• Facilitator’s job:Facilitator’s job:– Design experimentDesign experiment– Run experimentRun experiment– Analyze resultsAnalyze results– Confirm experimentConfirm experiment

Step 1: Step 1: Problem IdentificationProblem Identification

• What do managers and/or What do managers and/or employees see that need employees see that need improvement?improvement?

Step 2:Step 2:BrainstormingBrainstorming

• Identify critical variables in the Identify critical variables in the service that affect quality.service that affect quality.

• Open and honest discourse with all Open and honest discourse with all people involved.people involved.

• Decide which factors are Decide which factors are controllable and which are not.controllable and which are not.

Step 3: Step 3: Experiment DesignExperiment Design

• Using results from brainstorming Using results from brainstorming session, facilitator will design an session, facilitator will design an experiment.experiment.

• Management must understand this Management must understand this part, and needs to fully support the part, and needs to fully support the resources needed for it.resources needed for it.

Step 4:Step 4:ExperimentExperiment

• Use of ANOVA requires managers Use of ANOVA requires managers understand its use.understand its use.

• Facilitator, although in charge of Facilitator, although in charge of the experiment, must assure the experiment, must assure management’s understanding of management’s understanding of the process.the process.

Step 5:Step 5:AnalysisAnalysis

• Factors closest to target Factors closest to target specification identified.specification identified.

• Means to reduce controllable Means to reduce controllable variation produced.variation produced.

Step 6:Step 6:Confirm ExperimentConfirm Experiment

• Set up new system using data from Set up new system using data from experiment.experiment.

• Test and validate results.Test and validate results.

Conclusion:Conclusion:

• Best improvement is early in the process.Best improvement is early in the process.

• Use expert consulting help for full experiment Use expert consulting help for full experiment and implementation.and implementation.

• Successfully used in airlines, insurance, hotels Successfully used in airlines, insurance, hotels and restaurants.and restaurants.

• Quality is a major feature that sets a service Quality is a major feature that sets a service apart from the rest. apart from the rest.

Success StoriesSuccess Stories

• AT&T Bell Laboratories (Computer AT&T Bell Laboratories (Computer Response-Time Optimization).Response-Time Optimization).

• Chrysler Motors Engineering Chrysler Motors Engineering (Sheet-Molded Compound Process (Sheet-Molded Compound Process Improvement) Improvement) -finished products improved from -finished products improved from 77% to 96%.77% to 96%.-scrap was reduced from 16% to -scrap was reduced from 16% to 1.7%.1.7%.

• Companies design and produce Companies design and produce low-cost, highly reliable quality low-cost, highly reliable quality products and processes. products and processes.

• Cuts research, development, and Cuts research, development, and delivery time.delivery time.

• Allows engineers to develop Allows engineers to develop flexible technology for the design flexible technology for the design and production.and production.

SummarySummary

BibliographyBibliography

1)PRODUCT QUALITY MANAGEMENT BY 1)PRODUCT QUALITY MANAGEMENT BY Frank Moisiadis

2)2)TAGUCHI APPROACH TO DESIGN OPTIMIZATION FOR TAGUCHI APPROACH TO DESIGN OPTIMIZATION FOR

QUALITY AND COST Resit Unal & Edwin B. DeanQUALITY AND COST Resit Unal & Edwin B. Dean

3) 3) DOE-IBasicDesign of Experiments DOE-IBasicDesign of Experiments

Presented By Nutek, Inc. Presented By Nutek, Inc.

4) Introduction to Taguchi Method Wekipedia.4) Introduction to Taguchi Method Wekipedia.

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