Chất lượng là gì mà ai cũng đòi hỏi, có phải đúng là tiền nào của nấy. Đó là các câu hỏi được các doanh nghiệp luôn luôn đặt ra và suy nghĩ để duy trì và cải tiến. Đây cũng là môn học quan trọng dành cho các nhà quản trị tương lai
7 QC tools Property of ACT ( ACMA Centre for Technology ) 2007 PDF created with pdfFactory Pro trial version www.pdffactory.com Slide No Seven QC Tools Scatter Diagram Stratification Histogram Graph and Control Chart Cause and Effect Diagram Pareto Diagram Check Sheet Property of ACT ( ACMA Centre for Technology ) 2007 PDF created with pdfFactory Pro trial version www.pdffactory.com Slide No Sl.No Tools Function Check Sheet / Data Sheet To Collect the data in a simple manner and to prevent omitting the checks Pareto Daigram To pick up the important few problems from the trivial many Cause and Effect To reorganise the factors (causes) which are Diagram influencing the problem Presentation of data in a pictorial form for Graph and Control better understanding and see if the process Chart is under stable conditions Histogram To see the distribution pattern compared against the standard values Stratification To segregate data according to contributing sources.(Suppliers,machines,operators etc) Scatter Diagram To see relation between two sets of data Property of ACT ( ACMA Centre for Technology ) 2007 PDF created with pdfFactory Pro trial version www.pdffactory.com Slide No Check Sheet Solder Bath Temperature Checked by : Raised by : Take reading of temperature nearest to degree Time Temp (0C) Time Temp (0C) 0800 60 1300 61 0900 62 1400 58 1000 59 1500 63 1100 58 1600 63 1200 59 1700 59 Note : Power failure from 12.00 to 12.15 Hours Property of ACT ( ACMA Centre for Technology ) 2007 PDF created with pdfFactory Pro trial version www.pdffactory.com Slide No What is Check Sheet ? A Check sheet is a paper form on which item to be checked have been printed already so that data can be collected easily and concisely Its main purposes are two-fold : 1) To make data-gathering easy ; 2) To arrange data automatically so that they can be used easily later on Two Types of Data : Measurement data or Variable data Attribute data Property of ACT ( ACMA Centre for Technology ) 2007 PDF created with pdfFactory Pro trial version www.pdffactory.com Slide No Check sheets are of following types : a) Check sheet for production process distribution b) Defective item check sheet c) Defect location check sheet d) Defect cause check sheet Property of ACT ( ACMA Centre for Technology ) 2007 PDF created with pdfFactory Pro trial version www.pdffactory.com Slide No Check Sheet for Production Process Distribution: Checks Deviation Specification 8.300 Specification 10 Frequency 15 20 -10 -9 -8 -7 -6 -5 -4 -3 -2 -1 10 11 1 Total Property of ACT ( ACMA Centre for Technology ) 2007 PDF created with pdfFactory Pro trial version www.pdffactory.com Slide No 55 Defective Item Check Sheet: Product : Date : Manufacturing stage: Final inspection Type of defect: Scar,incomplete Section : Inspector’s name : crack,misshapen Lot no : Total no.inspected : 1525 Order no : Remarks : All items inspected Type Checks Subtotal Surface scars IIII IIII IIII Cracks IIII IIII I Incomplete IIII IIII IIII Mishappen III Others IIII II 17 11 IIII IIII I 26 Total : Total rejects 62 42 Property of ACT ( ACMA Centre for Technology ) 2007 PDF created with pdfFactory Pro trial version www.pdffactory.com Slide No Defect Location Check Sheet A A B 12 15 C 10 11 D B C D From the location matrix it is clear that most of the blow holes are occupied in the segment B2,B3,C2 & C3 Defect Location Matrix For Blowholes (50 Defective Components) Property of ACT ( ACMA Centre for Technology ) 2007 PDF created with pdfFactory Pro trial version www.pdffactory.com Slide No Defect Cause Check Sheet Mon Tue W ed Thu Fri Sat Equipment Operator AM PM oo ox x AM PM xx ooo AM PM ooo xxx xx AM PM AM PM AM oo xxxx oo oo xx A oo xxx oo xx B xx o Damage oo x Blowhole Poor finish Property of ACT ( ACMA Centre for Technology ) 2007 PDF created with pdfFactory Pro trial version www.pdffactory.com Crack Slide No Others 10 PM Quality Defective (Nos) Stratification 48% 50 40 30 20 18% 16% 12% 10 6% A B C D E Types of Defect Property of ACT ( ACMA Centre for Technology ) 2007 PDF created with pdfFactory Pro trial version www.pdffactory.com Slide No 66 What is Stratification : Stratification is the process of separation of data into categories It is normally done for identifying the categories contributing to the problem tackled Property of ACT ( ACMA Centre for Technology ) 2007 PDF created with pdfFactory Pro trial version www.pdffactory.com Slide No 67 Types of Stratification : A Material Based : 48% 50 Defective % 40 30 20 16 % 15% 10 A B C Supplier Defective Quality - Supplier Wise Property of ACT ( ACMA Centre for Technology ) 2007 PDF created with pdfFactory Pro trial version www.pdffactory.com Slide No 68 Types of Stratification : Quality Defective(Nos) B Quality Based : 48% 50 40 30 20 18% 16% 12% 6% 10 A B C D C Type of Defect Defects Data For Each Hour in a Shift Property of ACT ( ACMA Centre for Technology ) 2007 PDF created with pdfFactory Pro trial version www.pdffactory.com Slide No 69 Types of Stratification : C Worker Based : No of Defective 30 22% 25 20 15 10 5% 3% A B C Worker Defective Assemblies Property of ACT ( ACMA Centre for Technology ) 2007 PDF created with pdfFactory Pro trial version www.pdffactory.com Slide No 70 Types of Stratification : Production % D Machine Based : 100 90 80 70 60 50 40 30 20 10 57% 43% A B Machine Production Machine Wise Property of ACT ( ACMA Centre for Technology ) 2007 PDF created with pdfFactory Pro trial version www.pdffactory.com Slide No 71 Types of Stratification : Power Consumption % E Processing Based : 50 40 32% 30 26% 25% 20 12% 10 5% A B C D E Process Area Power Consumption Process Area Wise Property of ACT ( ACMA Centre for Technology ) 2007 PDF created with pdfFactory Pro trial version www.pdffactory.com Slide No 72 Scatter Diagram 4.5 Overall rating of the Session 4.4 4.3 4.2 4.0 y axis 430 x axis 4.1 3.9 3.8 3.7 3.6 3.5 3.4 100 150 200 250 300 350 400 450 500 550 600 650 Average Experience of Training Team (in days) Property of ACT ( ACMA Centre for Technology ) 2007 PDF created with pdfFactory Pro trial version www.pdffactory.com Slide No 73 What is Scatter Diagram : Scatter diagram is a graphical representation of relationship between two variables It can be between a Cause and Effect and between causes In 1837 J.F.W.Herswchal,an Englishman, used scatter diagram In 1950s Dr.K.Ishikawa popularized the use of scatter diagram Property of ACT ( ACMA Centre for Technology ) 2007 PDF created with pdfFactory Pro trial version www.pdffactory.com Slide No 74 Steps to draw Scatter Diagram : 1) Collect paired data (x,y) 2) Find the maximum and minimum values for both the x and y 3) Plot the data 4) Enter all necessary items Property of ACT ( ACMA Centre for Technology ) 2007 PDF created with pdfFactory Pro trial version www.pdffactory.com Slide No 75 The horizontal (x axis) and vertical (y axis) lines of the diagram: The measurement scales generally increase as you move up the vertical axis and to the right on the horizontal axis 4.5 4.4 Dependent variable (“effect”) 4.3 4.2 4.1 4.0 3.9 * Looking for relationships not cause & effect 3.8 Independent variable (“cause”) 3.7 3.6 3.5 150 200 250 300 350 400 450 Property of ACT ( ACMA Centre for Technology ) 2007 PDF created with pdfFactory Pro trial version www.pdffactory.com 500 550 600 Slide No 650 76 Overall rating of the Session Examples of Scatter Diagram : 4.5 4.4 4.3 4.2 4.0 y axis 4.1 430 x axis 3.9 3.8 3.7 3.6 3.5 3.4 100 150 200 250 300 350 400 450 500 550 600 650 Average Experience of Training Team (in days) Property of ACT ( ACMA Centre for Technology ) 2007 PDF created with pdfFactory Pro trial version www.pdffactory.com Slide No 77 Possibilities after plotting the points a Positive relationship b No correlation c Negative correlation d Positive and Negative correlation e Negative and Positive correlation Property of ACT ( ACMA Centre for Technology ) 2007 PDF created with pdfFactory Pro trial version www.pdffactory.com Slide No 78 n = 30 r = 0.9 n = 30 r = 0.6 n = 30 y y y 6 4 2 0 0 x Positive Correlation n = 30 r = 0.9 n = 30 y 6 4 2 x Positive Correlation May Be Present y r = 0.0 No Correlation r = 0.6 0 x Negative Correlation x Negative Correlation May Be Present Property of ACT ( ACMA Centre for Technology ) 2007 PDF created with pdfFactory Pro trial version www.pdffactory.com x Slide No 79 The Journey is Never Ending Property of ACT ( ACMA Centre for Technology ) 2007 PDF created with pdfFactory Pro trial version www.pdffactory.com Slide No 80 ... Centre for Technology ) 20 07 PDF created with pdfFactory Pro trial version www.pdffactory.com Slide No 30 Line Graph : 70 9 Qty Produced 70 0 662 550 376 400 330 273 275 250 Jan'03 Feb Mar Apr May... 52 Scratch 42 146 21 73 Pinhole 20 166 10 83 Crack 10 176 88 Stain 182 91 Gap 186 93 Others 14 200 100 Total 200 - 100 - Property of ACT ( ACMA Centre for Technology ) 20 07 PDF created with pdfFactory... Technology ) 20 07 PDF created with pdfFactory Pro trial version www.pdffactory.com Slide No 27 Graph and Control Chart UCL C/L LCL Property of ACT ( ACMA Centre for Technology ) 20 07 PDF created