POLITECNICO DI TORINO COLLEGE OF ENGINEERING DEPARTMENT OF MECHANICAL AND AEROSPACE ENGINEERING MASTER OF SCIENCE IN AUTOMOTIVE ENGINEERING Final Project APPLICATION OF WCM METHODOLOGIES FOR FIRST TIME QUALITY IMPROVEMENT University Supervisor: Company Supervisor: Prof. Marco Gobetto Ing. Matteo D’Antino Prof. Paolo De Blasi Gerardo Rosa Candidate: Luca Gironda S241491 academic year: 2017 – 2018 2 Table of Contents Chapter 1 Introduction ............................................................................................................... 8 Chapter 2 WCM ........................................................................................................................ 10 2.1 Origins ................................................................................................................................ 10 2.2 Mission ............................................................................................................................... 11 2.3 Structure ............................................................................................................................. 12 2.3.1 Technical Pillars ....................................................................................................................... 13 2.3.2 Managerial Pillars .................................................................................................................... 25 Chapter 3 QC Quality Control ............................................................................................... 28 3.1 QC Indicators ................................................................................................................... 28 3.2 WCM Tools for QC ........................................................................................................... 30 3.3 Statistical Process Control ............................................................................................... 37 Chapter 4 The Plant and the Product .................................................................................... 41 4.1 The Plant ............................................................................................................................ 41 4.2 The Product ....................................................................................................................... 42 4.3 Quality Control ................................................................................................................. 43 4.4 Gear wheels ....................................................................................................................... 46 Chapter 5 PLAN: Application of WCM methodologies for FTQ Improvement .......... 49 5.1 Definition of FTQ ............................................................................................................. 49 5.2 Identification of the problem ......................................................................................... 51 5.3 5W1H .................................................................................................................................. 51 5.3.1 Fast-response Showcase .......................................................................................................... 52 5.3.2 5W1H Crown wheel – Pinion couple .................................................................................... 54 5.3.3 5W1H 5th gear wheels ............................................................................................................. 55 5.4 4M Analysis ....................................................................................................................... 58 5.4.1 4M Analyis Crown Wheel – Pinion couple .......................................................................... 58 5.4.2 Standard Kaizen for defective Crown wheels ..................................................................... 59 5.4.3 Major Kaizen for defective secondary shaft Pinions ........................................................... 62 5.4.4 Major Kaizen for defective 5th gear wheels .......................................................................... 64 5.5 Design of Experiments for Defective Pinions ............................................................... 66 5.5.1 Database of defects .................................................................................................................. 67 5.5.2 Output from Database of defects .......................................................................................... 69 5.5.3 Definition of Experiments....................................................................................................... 73 5.5.4 Database of Experiments ........................................................................................................ 74 5.5.5 Output from Database of Experiments ................................................................................ 76 5.6 Design of Experiments for Defective 5th Gear Wheels ................................................ 96 3 Chapter 6 DO: Application of Countermeasures for FTQ Improvement ..................... 103 6.1 Noise of secondary shaft pinion - differential crown wheel couple ....................... 103 6.1.1 X-Matrix for Shaving Machine ............................................................................................. 104 6.1.2 QM-Matrix for Shaving Machine ......................................................................................... 104 6.1.3 5QFZD – Five Questions for Zero Defects .......................................................................... 104 6.2 Noise of 5th gear couple .................................................................................................. 105 Chapter 7 CHECK: Monitor of Obtained Results .............................................................. 106 7.1 Noise of secondary shaft pinion - differential crown wheel couple ....................... 107 7.2 Noise of 5th gear couple ................................................................................................. 108 7.3 Reduction of Defects ....................................................................................................... 109 Bibliography .............................................................................................................................. 110 Sitography .................................................................................................................................. 110 4 Figures Chapter 1 Introduction ............................................................................................................... 8 Chapter 2 WCM ........................................................................................................................ 10 2.3.0.1 WCM Pillars ................................................................................................................ 13 2.3.1.1 7 Steps of SAF ....................................................................................................................... 14 2.3.1.2 7 Steps of CD ........................................................................................................................ 15 2.3.1.3 7 Steps of FI ........................................................................................................................... 16 2.3.1.4a 7 Steps of AM ..................................................................................................................... 17 2.3.1.4b 7 Steps of WO ..................................................................................................................... 18 2.3.1.5 7 Steps of PM ........................................................................................................................ 19 2.3.1.6 7 Steps of QC ........................................................................................................................ 20 2.3.1.7 7 Steps of LOG ...................................................................................................................... 21 2.3.1.8 7 Steps of EEM / EPM ......................................................................................................... 22 2.3.1.9 7 Steps of PD ......................................................................................................................... 23 2.3.1.10 7 Steps of ENV .................................................................................................................... 24 Chapter 3 QC Quality Control ................................................................................................ 28 3.1.0.1 Costs of non-quality ................................................................................................... 29 3.2.0.1 Kaizen approach ......................................................................................................... 31 3.2.0.2 4M Analysis Ishikawa diagram ................................................................................ 31 3.2.0.3 4M Analysis procedures ............................................................................................ 33 3.2.0.4 Five questions for zero defects Machine ................................................................. 34 3.2.0.5 Five questions for zero defects Man......................................................................... 35 3.2.0.6 Five questions for zero defects Method ................................................................... 35 3.2.0.7 Five questions for zero defects Material .................................................................