I.3 Philosophy and History Some Goals of Manufacturing Some Goals of Manufacturing Various Paradigms Various Paradigms Some Aspects of Taguchi’s Philosophy Some Aspects of Taguchi’s Philosophy –On-Line and Off-Line Quality Control – Design Aspects

Some Goals The Quality Timeline

Paradigms The Inspection Paradigm Inspect Output To Remove Unsatisfactory Product Inspect Output To Remove Unsatisfactory Product

Paradigms Shewhart’s Paradigm “Can’t Inspect Quality Into A Product” “Can’t Inspect Quality Into A Product” Detect And Correct Quality Problems By Monitoring The Manufacturing Process Detect And Correct Quality Problems By Monitoring The Manufacturing Process Two Types Of Variation In A Manufacturing Process Two Types Of Variation In A Manufacturing Process

Paradigms Shewhart’s Paradigm - Terminology Shewhart: Assignable Cause Variation (ACV) and Chance Causes Of Variation (CCV) Shewhart: Assignable Cause Variation (ACV) and Chance Causes Of Variation (CCV) Deming: ACV=Local Faults, Special Causes, CCV=Common Cause Variation Deming: ACV=Local Faults, Special Causes, CCV=Common Cause Variation Juran: ACV=Sporadic Problems CCV=Chronic Problems Juran: ACV=Sporadic Problems CCV=Chronic Problems

Paradigms Shewhart’s Paradigm Objective Monitor The Process To Detect When ACV Is Present. Monitor The Process To Detect When ACV Is Present. – How Do You Detect ACV? Control Charts

Paradigms Shewhart’s Paradigm Two Ways To Improve Quality Eliminate Assignable Causes To Bring Process Into Statistical Control Eliminate Assignable Causes To Bring Process Into Statistical Control Improve The System By Reducing Common Cause Variation Improve The System By Reducing Common Cause Variation

Paradigms Tweaking The Variation Paradigm: The Variation/Complexity Paradigm

Paradigms The Variation/Complexity Paradigm Paraphrase Deming - “Reduce Variation And Complexity And You Improve Quality” Paraphrase Deming - “Reduce Variation And Complexity And You Improve Quality”

Paradigms Deming and Juran Originally Found That 80 to 85% Of The Quality Problems Required Management’s Input In Order To Correct. Originally Found That 80 to 85% Of The Quality Problems Required Management’s Input In Order To Correct. Over The Years This Percentage Increased To Where They Found That 94 to 96% Of Quality Problems Were Systemic! Over The Years This Percentage Increased To Where They Found That 94 to 96% Of Quality Problems Were Systemic!

Paradigms Deming And Juran’s Extension Need Management’s Involvement Need Management’s Involvement

Paradigms Deming and Taguchi Customer Satisfaction is the Determining Factor in Product Design Customer Satisfaction is the Determining Factor in Product Design – Taguchi - Quality is measured in terms of loss to society -Wring Out the Variation -Wring Out the Variation – Deming and Juran - Controlling the Process (On-Line QC) – Taguchi - Design Robust (Rugged) Processes and Products (Off-Line QC)

Paradigms Taguchi - Another Way To Improve Quality Build Rugged/Robust Products And Processes By Making Things Insensitive To Unknown Or Uncontrollable Sources Of Variation Build Rugged/Robust Products And Processes By Making Things Insensitive To Unknown Or Uncontrollable Sources Of Variation

Some Aspects of Taguchi’s Philosophy Prevention Rather Than Detection Rather Than Detecting Defects, Let’s Design Quality Into The Product Right From The Beginning. “An Ounce of Prevention...” Rather Than Detecting Defects, Let’s Design Quality Into The Product Right From The Beginning. “An Ounce of Prevention...”

Some Aspects Taguchi’s Approach During the 50’s and 60’s Developed A Philosophy and Methodology Concerning Product Design and Production During the 50’s and 60’s Developed A Philosophy and Methodology Concerning Product Design and Production

Some Aspects Design Aspects of Taguchi’s Philosophy Robust Products And Processes Through “Engineering Design” (Statistical Design Of Experiments, DOE, Plays A Role Here) Robust Products And Processes Through “Engineering Design” (Statistical Design Of Experiments, DOE, Plays A Role Here) – Parameter Design  Choose Parameter (Factor) Levels To – Optimize Process or Product Performance – Mitigate Uncontrollable Factors

Some Aspects Design Aspects of Taguchi’s Philosophy: Factors Control Factors Control Factors – “Easily” controlled sources of variation Noise Noise – Uncontrollable  External - Environmental Goal - Design Product to Be Insensitive to Noise Factors