quality development 2016 - mdhzoomin.idt.mdh.se/course/ppu404/documents/quality development...

2016-04-12 Antti Salonen

Quality development

What is Quality?

“Quality” means those features of products which meet customer needs and thereby provide customer satisfaction.

“Quality” means freedom from deficiencies.

Two types of deficiensies

Design related

Manufacturing related

•  Faulty raw material •  Poor material handling •  Faulty machines •  Human errors

Manufacturing related deficiensies

Process improvement Process quality

Time

Deviations!

Upper limit

Lower limit

Process improvement Process quality

Time

Process improvement Process quality

Time

7QC

• The Ishikawa diagram • The Check sheet • The Control chart • The Histogram • The Pareto chart • The Scatter diagram • Stratification

The seven basic tools of quality

7QC: The Ishikawa diagram

Main problem

Man Method Machine

Material Environment Measurement system

Management

7QC: The Check sheet

7QC: The Control chart

7QC: The Histogram

7QC: The Pareto chart

Småstopp KB w603

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Stegbalk 18 12 16 22 3 10 11 15 19 20

Station

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Short stops

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7QC: The Scatter diagram How do you set the line?

Linear regression!

7QC: Stratification

Why do machines produce defects?

Common machine related problems

● Wear and tear ● Vibrations and movements ● Missadjustments and poor handling ● Environmental disturbances

Quality maintenance (TPM)

1 Control of quality standards and parameters 2 Study where the quality defects appear 3 Choose a pilot equipment for the implementation of quality maintenance 4 Check functions, operations and setup procedures of the equipment 5 Restore the condition of the equipment 6 Perform PM-analysis 7 Eliminate all factors, contributing to defects 8 State operating conditions and optimize the equipment and change-over procedures 9 Identify defects 10 Restore or improve 11 Evaluate standard levels and determine which components to monitor 12 Determine the condition for defect free production 13 Reduce the number of points for inspection 14 Specify standard values for the inspection points 15 Make a draft for a quality matrix 16 Evaluate the content of the inspection standard 17 Evaluate and adjust the standards and inspection points through trend analysis

Phase 1

Quality maintenance (TPM)

Phase 2

Phase 3

Phase 4

Advanced concepts for Quality development ●  Design Of Experiments Multiple factor analysis ●  PM-analysis ●  Geometry measurement (tooling machines)

Design Of Experiments

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Temperature C

Catalyst A

Concentration B

Design Of Experiments

PM-analysis Physical  analysis   Cons-tuent  

condi-ons  Primary  4M   Secondary  4M   Established  op-mal  condi-ons   Abnormali-es   Suggested  

improvements  

Step  2   Step  3   Step  4.1   Step  4.2   Step  5   Step  6   Steps  7  and  8  The  distance  (A)  varies  between  the  edge  (B)  of  the  cuCng  tool  and  the  end  posiEon  (C)  of  the  pipe  

3:  The  posiEon  of  the  pipe  varies  

3:1  The  gripper  don't  pull  the  pipe  to  the  right  length   3.1.1  Locking  rolls  are  worn   3.1.1  Max  3mm  deterioraEon   3.1.1  OK!   Not  presented  

3.1.2  Too  low  force  in  the  locking  piston   3.1.2  Minimum  80  N   3.1.2  Too  low      3.1.3  Oil  on  the  locking  rolls   3.1.3  No  oil   3.1.3  Oil  present      3.1.4  High  amount  of  oil  on  the  pipes   3.1.4  No  oil   3.1.4  Oil  present      

3.1.5  The  pipe  is  misaligned  in  the  frame   3.1.5  The  pipe  should  run  smooth   3.1.5  Resistance      3.1.6  Debri  in  the  steering  mechanism   3.1.6  Absolute  clean   3.1.6  Not  clean      3.1.7  High  flexibility  in  frame   3.1.7  Max  30  N  on  inner  tube   3.1.7  To  high  force      3.1.8  Debri  on  the  door   3.1.8  Absolute  clean   3.1.8  Not  clean      3.1.9  Doesn't  grip  because  of  resistance  in  gripper  mechanism  

3.1.9  No  resistance   3.1.9  Some  resistance      

           3:2  The  gripper  doesn't  move  the  right  distance   3.2.1  Play  in  slewing  bracket   3.2.1  Max  2mm  play   3.2.1  Play  exists      

3.2.2  Loose  bracket   3.2.2  Fastened   3.2.2  Loose      3.2.3  Air  pressure  too  low   3.2.3  Pressure  5KPa   3.2.3  OK  (if  enough)  

   3:3  The  posiEon  of  the  tube  changes  a[er  the  gripper  has  released  

3.3.1  The  pipe  bounce  on  the  door   3.3.1  No  Bounce   3.3.1  Not  evaluated!      

3.3.2  Skew  pipe  is  pulled  up   3.3.2  Max  skewness  0.1mm/100mm  3.3.2  Skewness  occurs      3.3.3  Resistance  in  the  locking  mechanism  makes  it  pull  the  pipe  

3.3.3  No  resistance   3.3.3  Some  resistance          

3.3.4  Pipe  bounce  when  the  cu]er  posiEons  too  late  

3.3.4  Cu]er  should  posiEon  when  pipe  is  released  

3.3.4  Occasionaly          

3.3.5  Wear/grades  on  the  top  of  the  door   3.3.5  No  wear  or  grades   3.3.5  Damaged!                  

Machine geometry

Machine geometry

Ball bar meassuring

Ball bar meassuring

What is Quality?

“Quality” means those features of products which meet customer needs and thereby provide customer satisfaction.

Higher quality in this sense usually “costs more.”

“Quality” means freedom from deficiencies. In this sense, higher quality usually “costs less.”

Practical advice

•  Use the 7QC tools •  Use multiple data sources

•  Your own observations •  The operators’ statements Compare these •  Formal instructions etc.

•  Ask the quality deepartment