1. ©
Basic Quality Tools
1. Check Sheets
2. Pareto Analysis
3. Flow Charts
4. Cause & Effect Diagram
5. Histograms
6. Scatter Diagrams
7. Control
Charts

2. ©
Check Sheets
Check Sheet is a
gathering
interpretation tool.
dataand

3. Check Sheets
©
• Want to find out cause-wise defects
Defects
1
2
3
4
5
6
Total
Missing
component
III
IIII
II
I
III
IIII
18
No solder
II
III
I
IIII
10
Wrong
Insertion
IIII
I
IIII
II
IIII
20
Shorts by
component
II
IIII
III
11
Total
11
9
17
59
IIII
II
9
6
7

4. ©
Check Sheets
• More defects on the last day of the
week.
• Missing components and Wrong
Insertion occur more frequently.

5. ©
Check Sheets
• Check sheet is a data pattern
detector.
• Check sheet to be used during
problem definition stage and after
implementation stage.

6. ©
Check Sheets
1. Distinguishing between fact and
opinion.
2. Gathering data about how
often a problem is occurring.
3. gathering data about the type
of problem occurring.

7. ©
Check Sheets
1. Confirmation Check Sheet –
List of steps which must be
complete before shipping a
product.
2. Defect Location Sheet
identify problem areas.
–

8. ©
Pareto Analysis
The Pareto Principle states that
only a "vital few" factors are
responsible for producing most of
the problems.
Majority of problems (80%) are
due to a few key causes (20%). If
we correct these few key causes,
we will have a greater probability
of success.

9. ©
Pareto Analysis
Causes
Frequency
Breakout
37
Hanger
4
Tundish nozzle choking
4
Dummy bar obstraction
5
Overflow
8
Sheer trouble
7
Tundish nozzle erosion
6
Withdrawal problem
12
Bad stream
1
Auto control failure
1

10. ©
Pareto Analysis
Causes
% Freq. % Cum. Freq.
Breakout
44
44
Withdrawal problem
14
58
Overflow
9
67
Sheer trouble
8
75
Tundish nozzle erosion
7
82
Dummy bar obstraction
6
88
Hanger
5
93
Tundish nozzle choking
5
98
Bad stream
1
99
Auto control failure
1
100

11. %
©
Pareto Analysis
100
80
60
40
20
0
58
67
75 82
100
93 98 99
88
44
14
9
8
7
6
5
5
1
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ut
o
1

12. ©
Flow Chart
A flow chart is defined as
a pictorial representation
describing a process.

13. ©
Flow Chart
1. A
diagrammatic
picture
showing all steps or stages in
a process.
2. Flow charts help facilitate a
greater understanding of the
entire process by identifying
where problems have occurred
or may occur.
3. You cannot improve a process
until everyone agrees what the

14. ©
Cause & Effect (C-E) Diagram
1. Also called Ishikawa Diagram,
Fishbone Diagram.
2. Used to sort out
causes of problems.
potential
3. Organizes theories by causeand-effect relationships.

15. ©
Cause & Effect (C-E) Diagram
4. Provides
a
guide
process analysis.
for
5. Highlight likely root causes.

16. ©
Machine
Quench
time
Method
Coke temp.
Nozzle
condition
Water flow
rate
Spot quenching
Flue temp.
Coke
moisture
Drainage time
Quench
car speed
Man
Coke distribution in
quench car

17. ©
Histogram
1. Graphical representation of
individual measured values
according to frequency or
relative
frequency
of
occurrence.
1. Used to show distribution
shape
for
one
variable
(location, dispersion).

18. Daily production data (t)
240
230
220
210
208
200
190
180
37
33
29
25
21
17
13
9
5
170
1
©
Histogram

19. Frequency
©
Histogram
9
8
7
6
5
4
3
2
1
0
185 190 195 200 205 210 215 220 225 230
Daily Production (t)

20. ©
Scatter Diagrams
1. Used to visualize relationship
between two variables.
Features of a single product.
Product output & process input.
Two different products.
2. Issues
Strength of correlation,
non-linear relationships.

21. Scatter Diagrams
©
95
Tensile Strength
90
85
80
75
70
65
60
140
160
180
Hardness
200

22. ©
Control Charts
1. Purpose
Separate common (inherent)
and special causes.
Monitor process over time.
2. Used
to
Identify
Cause Variation.
Process
patterns
shifts
Special
/
Cyclic

23. Control Charts
Means ( X-bar)
©
Xbar and R Chart for : Major OD Minimum
129.85
129.75
MU=129.7
129.65
129.55
LCL=129.52
129.45
Subgroup 0
0.3
Ranges
UCL=129.88
5
10
15
UCL=0.3076
0.2
0.1
R=0.09412
0.0
LCL=0.000