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
0
100
200
300
400
500
600
700
800
900
7 8 4 6 14 5 2 1 21 13 9 17
Stegbalk 18 12 16 22 3 10 11 15 19 20
Station
Anta
l
Short stops
Qu
an
tity
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
124
116
121
113
89
131
84
130
(-)
(+)
(-)
(-)
(+)
(+)
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