Digging Deeper Into Digging Deeper Into Quality ToolsQuality Tools
Process and Tools Training Toolbook-PQ Systems
-http://www.pqsystems.com/
-Information in this presentation is derived from PQ Systems
Pareto Diagram
47
1910 7 2 2 1
35
66%
81%90%
38%
96% 98% 99% 100%
0
20
40
60
80
100
120
0%
25%
50%
75%
100%
Pareto’s Law• The Pareto principle (also known as
the 80-20 rule, the law of the vital few Vs. trivial many.
• 80% of the consequences stem from 20% of the causes. – 80% of income in Italy went to 20% of the
population. – "80% of your sales come from 20% of your
clients.“– “80% of discipline problems come from 20% of
the students”
Pareto DiagramP. 145 Tool Book
What is it?- A bar chart which ranks related measures
in decreasing order of occurrence
- A tool to separate the significant aspects
from the trivial ones
- A way to identify “the culprit's” in a problem and focus improvements in the right area
Pareto DiagramHow is it made?
1. Select logical categories.2. Specify the time period.3. Collect the data.4. Construct a frequency table.5. Draw and scale the horizontal and
vertical axes.6. Draw and label the bars for each
category7. Draw the cumulative percentage line.8. Review the results of the Pareto.
Pareto Diagram SampleStep 3- Collect The Data (149 Tool Book)
Category Total
Unexcused Absences 35
Drug & Alcohol Abuse 7
Tardiness 47
Illegal Parking 2
Dress Code Violation 1
Vandalism 2
Class Disruption 19
Fighting & Assault 10
Total 123
Step 4- Construct Frequency Table
Category Frequency Cumulative Frequency
1. Tardiness 47 47
2. Unexcused Absences 35 82
3. Class Disruption 19 101
4. Fighting & Assault 10 111
5. Drug & Alcohol Abuse 7 118
6. Illegal Parking 2 120
7. Vandalism 2 122
8. Dress Code Violation 1 123
Total 123
Step 5- Draw & Scale Horizontal & Vertical Axes
123
0
100%
75%
50%
25%
0
Step 6- Draw & Label The BarsStep 7- Draw Cumulative % Line
47
1910 7 2 2 1
35
66%
81%90%
38%
96% 98% 99% 100%
0
20
40
60
80
100
120
0%
25%
50%
75%
100%
In-Process Measure Example
Estimation Check Sheet Weekly
Class Errors
Hour 1 - Mr. Albert
Strategy 1 2 3 4 5 6
Total1-6
Week12-Sep
19-Sep
29-Sep 3-Oct
10-Oct 17-Oct
Addition 2 2 1 1 0 0 6
Subtraction 2 2 3 1 2 1 11
Multiplication 7 8 7 8 7 7 44
Division 10 11 10 11 12 10 64
Application 11 11 10 11 12 12 67
28 students
Total Errors 32 34 31 32 33 30 192
Number of Students 28 28 28 28 28 28
Estimation Check Sheet SkillsWeeks 1- 6
67 64 44 11 6 192
35%
68%
91%
97%100%
0
20
40
60
80
100
120
140
160
180
Application Division Multiplication Subtraction Addition Total N
Item
Nu
mb
e o
f E
rro
rs
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
Per
cen
tag
e
This bar represents the total (N
) of your pareto.
Pareto Diagram•Let’s practice the “pareto diagram”
Pareto Diagram
Answer Key
25
9 6 3 1 1
100%98%96%
56%76%
89%
0
10
20
30
40
Student Vs.Teacher
Student Vs.SecurityOfficer
Student Vs.Principal
Intruder Vs.Teacher
Parent Vs.Teacher
Intruder Vs.SecurityOfficer
0%
20%
40%
60%
80%
100%
Frequency Total Cumulative Percentage Total
Pareto Diagram- Safety ConcernsCheck Sheet Frequency Table
Type of Assault Frequency
Total
Student Vs. Security Officer
Intruder Vs. Security Officer
Intruder Vs. Teacher
Parent Vs. Teacher
Student Vs. Teacher
Student Vs. Principal
9
1
3
1
25
6
Total 45
Pareto Diagram- Cumulative Table
Type of Assault Cumulative
Total
1.) Student Vs. Teacher (25)
2.) Student Vs. Security Officer (9)
3.) Student Vs. Principal (6)
4.) Intruder Vs. Teacher (3)
5.) Parent Vs. Teacher (1)
6.) Intruder Vs. Security Officer (1)
25
34
40
43
44
45
Total 45
Completed Pareto Diagram
25
9 6 3 1 1
100%98%96%
56%76%
89%
0
10
20
30
40
Student Vs.Teacher
Student Vs.SecurityOfficer
Student Vs.Principal
Intruder Vs.Teacher
Parent Vs.Teacher
Intruder Vs.SecurityOfficer
0%
20%
40%
60%
80%
100%
Frequency Total Cumulative Percentage Total