Chapter
8:
Dr Le Thai Phong
Foreign Trade
University
Statistical
tools
applied
in
T: 0975.055.299
E:lethaiphong@gmail.com
quality
management
QUALITY MANAGEMENT:
Dr. Đào Minh Anh
Chapter 1: Quality Management:
Faculty of Business Administration
T: 094.808.9481
Foundation
E: anhdm@ftu.edu.vn
QUALITY MANAGEMENT SYSTEM
PARTNERSHIP
FACTS/FIGURES
CONTINOUUS IMPROVEMENT
SYSTEM APPROACH
PROCESS APPROACH
INVOLVEMENT OF PEOPLE
LEADERSHIP
CUSTOMER FOCUS
CUSTOMER SATISFACTION
2
The Seven QC (Quality Control) Tools
• What are The Seven QC tools (7 basic Tools)?
• A collection of tools adapted from statistics
and industrial engineering.
• Basic techniques that are used in solving
problems concerning quality, costs and
production problems that arise in the
workplace.
• They have been used extensively to support
quality improvement efforts.
7 tools
• 1.Flow charts and Graphs
• 2. Cause and effect diagram
• 3. Check sheet
• 4. Pareto Diagrams
• 5. Histograms
• 6.Control Charts/ Run charts
• 7.Scatter Diagrams
7 tools
1. Flowcharting – what is done?
2. Cause and effect analysis and brainstorming– what
causes the problems?
3. Check sheets/tally charts – how often is it done?
4. Pareto analysis – which are the big problems?
5. Histograms – what do overall variations look like?
6. Control charts – which variations to control and how?
7. Scatter diagrams – what are the relationships between
factors?
Basic Quality Tools
Copyright ©2018 McGraw-Hill Higher Education. All rights reserved. No reproduction or distribution without
Flowchart
• A diagram that uses graphic symbols to depict
the nature and flow of the steps in a process.
• For quality improvement, flowchart help to
provide a clear understanding of how a
process works.
Flowchart
• SIPOC stands for Suppliers-Inputs-Process-Outputs
Customers.
• For analyzing manufacturing or service processes, we
often start with a high-level flowchart called a SIPOC
diagram.
• It provides a broad overview of the key elements in
the process and help to explain who is the process
owner, how inputs are acquired, who the process
serves, and how it adds value.
Flowchart
Figure 9.5
General Structure of a
SIPOC Diagram
Figure 9.6
Example of a
SIPOC Diagram
Flowchart
• Value stream map: The process flows in a manner
similar to an ordinary process map.
– Highlight value-added versus non-value-added
activities
– Include times that activities take
• Takt time is the ratio of the available work time to the
required production volume necessary to meet
customer demand.
Flowchart
Figure 9.8
New Small Adjustment Request Form Process Flowchart for Marketing and Sales Department
Flowchart: benefit
• Promote process understanding
• Tool for training
• Identify problem areas & improvement
opportunities
• Depict customer-supplier relationship
Flow chart
Flowchart
• You are applying a scholarship for master
degree in the USA. Please use a micro
flowchart to describe this process.
• GROUP WORK
Check sheet
• It is used to systematically record and compile
data from historical sources, or observations
as they happen, so that patterns and trends
can be clearly detected and shown.
Cheek sheet
• Tabular format
– To count how often something happens
• Location format
– To show the exact physical location of a defect or
characteristic
• Graphic format
– Data can be recorded and displayed at the same
time
Check sheet: tabular format
Check sheet: location format
Check sheet: graphic format
Cheek sheet: example
Check sheet: how to do?
• 1. Agree on definition of the events or
conditions being observed.
• 2. Decide who will collect data, over what
period, and from what sources.
• 3. Design a Check Sheet form that is clear,
complete and easy to use.
• 4. Collect the data consistently and accurately
Check sheet: example
• You are QC at a furniture firm. Here is the record:
• Mon: painting 3, scratch 3
• Tue: painting 2, smooth 4, scratch 1
• Wes: painting 5, smooth 2, length: 3
• Thus: painting: 3, scratch 2, length: 1, smooth 2,
height: 1
• Fri: painting 4, scratch: 3, smooth: 3, length: 2, height:
1
=> USE THE CHECK SHEET (TABULAR FORMAT) TO
PRESENT THE QUALITY PROBLEMS OF THE COMPANY’S
PRODUCT. WHAT PROBLEMS OCCUR MOST OFTEN?
Pareto diagram
• A series of bars whose heights reflect the
frequency or impact of problems. The bars are
arranged in descending order of height from
left to right. This means the categories
represented by the tall bars on the left are
relatively more significant than those on the
right
Pareto diagram
Pareto diagram
Pareto diagram
• 1. Collect the data
• 2. Order the data
• 3. Calculate the accumulated percentage
• 4. Label the vertical axis
• 5. Label the horizontal axis
• 6. Plot the bars
• 7. Add up the count
• 8. Add up the cumulative line
• 9. Add title, legend, date
• 10. Analyze the diagram
Histogram
• A vertical bar chart that depicts the
distribution of a set of data
Histogram: when?
• Summarize large data sets graphically
• Compare measurement to specification
• Communicate information to teams
• Assist in decision making
Histogram: how?
• Count the number of data point
• Summarize on a tally sheet
• Compute the range
• Determine number of intervals
• Compute interval width
• Determine interval starting points
• Count number of points in each interval
• Plot the data
• Add title and legend
Cause-and-Effect diagram
• A graphic tool that helps identify, sort, and
display possible causes of a problem or quality
characteristic.
• Cause & effect diagram = Ishikawa diagram =
fishbone diagram
Cause-and-Effect diagram
Cause-and-Effect diagram
Cause-and-Effect diagram
4M1E
Cause-and-Effect diagram
Cause-and-Effect diagram
• 1. Select the most appropriate cause & effect
format.
• 2. Generate the cause needed to build a cause and
effect diagram.
• 3. Construct the cause & effect diagram.
• 4. Make sure every one agrees on the problem
statement.
• 5. Include as much information as possible.
• 6. Interpret or test for Root cause.
Cause-and-Effect diagram
• Technique: BRAINSTORMING
Cause & effect diagram
• Causes of traffic jam in Hanoi
Control chart
• A statistical tool used to distinguish between
process variation resulting from common
causes and variation resulting from special
causes
EXERCISE 1
Exercise 1
EXERCISE 2
EXERCISE 3
Thank you!