The document discusses fishbone analysis (also known as Ishikawa diagram), which is a tool for systematically analyzing the potential causes of quality, process, or project problems. It provides the following key points:
1. Dr. Kaoru Ishikawa invented the fishbone diagram to systematically analyze the effects and causes that contribute to those effects.
2. The fishbone diagram looks like the skeleton of a fish, with the "head" representing the problem/effect and the "bones" and sub-branches representing categories of causes and specific potential causes.
3. Basic steps for constructing a fishbone diagram include identifying the problem/effect, categorizing potential cause factors, brainstorming specific causes within
2. Fishbone Diagram –
Problem Analysis Tool
What is a Fishbone diagram?
Dr. Kaoru Ishikawa, a Japanese quality control
statistician, invented the fishbone diagram.
Therefore, it may be referred to as the Ishikawa
diagram.
The fishbone diagram is an analysis tool that
provides a systematic way of looking at effects
and the causes that create or contribute to those
effects.
3. Fishbone Diagram –
Problem Analysis Tool
Because of the function of the fishbone diagram,
it may be referred to as a cause-and-effect
diagram. The design of the diagram looks much
like the skeleton of a fish. Therefore, it is often
referred to as the fishbone diagram.
4. Fishbone Diagram –
Problem Analysis Tool
The value of the fishbone diagram is to assist
teams in categorizing the many potential causes
of problems or issues in an orderly way and in
identifying root causes.
5. Usefulness of Fishbone
Analysis
it can be used when the team...
- needs to study a problem/issue to determine the root
cause
- wants to study all the possible reasons why a process is
beginning to have difficulties, problems, or breakdowns
- needs to identify areas for data collection
- wants to study why a process is not performing properly
or producing the desired results
6. Tools on Fishbone diagrams
The 4 W's of the Fishbone diagram should be
considered. The 4 W's are:
1. What - refers to questions concerning objects such as
machines and materials,
2. Why - which is concerned with questions on the
conditions such as motivation,
3. When - refers to problems concerning the time
sequence in the process such as the time of day or
sequence in production,
4. Where - is concerned with the effects associated with
place, such as a production line, branch office, or
loading dock.
7. Tools on Fishbone diagrams
For manufacturing problems, the 5 M's are a
useful tool in finding possible causes to a
problem.
The 5 M's are characterized as
- manpower,
- materials,
- methods,
- machines, and
- measurements.
8. Tools on Fishbone diagrams
For problems that are being examined in the
service industry, the 5 P's can be used to develop
the Cause Effect (CE)/Fishbone diagram:
- People (employees)
- Provisions (supplies)
- Procedures (processes)
- Place (environment)
- Patrons (customers)
9. How does it look like? An
example…
Situation: The goal of not meeting a
deadline is influenced by a number of
factors.
The diagram (that follows) depicts 4
broad categories under which are
grouped causes that we have identified
as driving forces or obstacles.
10. Rules/Techniques of
Fishbone Analysis
Basic Steps:
1. Draw the fishbone diagram....
2. List the problem/issue/goal to be studied in the
"head of the fish". (1st
level – main line)
3. Label each "bone" of the "fish". (2nd
level). List
each 2nd
level cause to the 1st
level.
4. The major categories for the 2nd
level are typically
utilized as:
11. An example of a fishbone
diagram
An example: Problem - Not meeting deadline
12. Fishbone diagram in
Manufacturing environments
FISHBONE DIAGRAM
Goal
Measurement Materials Methods
Environment People Machines
Broad category
13. Rules/Techniques of
Fishbone Analysis
5. Use an idea-generating technique (e.g.,
brainstorming) to identify the factors within
each category that may be affecting the
problem/issue and/or effect being
studied.This is known as the 3rd
level. The
team should ask... "What are the machine
issues affecting/causing..."
14. Rules/Techniques of
Fishbone Analysis
6. Repeat this procedure with each factor
under the category to produce sub-factors.
Continue asking, "Why is this happening?“
(4th
level) and put additional segments in
each factor and subsequently under each
sub-factor.
7. Continue until you no longer get useful
information as you ask, "Why is that
happening?"
15. Rules/Techniques of
Fishbone Analysis
8. Analyze the results of the fishbone after
team members agree that an adequate
amount of detail has been provided under
each major category. Do this by looking for
those items that appear in more than one
category. These become the 'most likely
causes".
16. Rules/Techniques of
Fishbone Analysis
9. For those items identified as the "most likely
causes", the team should reach consensus on
listing those items in priority order with the first
item being the most “probable” cause.
Two examples of fish diagrams follow which
includes an analysis of a company’s
performance.
17. Decrease cost
Overhead
Distribution
Product
Financing
Increase Margin
Increase Price
Add Value
Increase Demand
Increase Gross Revenue
Increase Existing
Product Volume
Differentiate
Product
Increased
Feature/Function
Real
Feature/Function
Product
Distribution
Quality
Features
Options
Warranties
Sizes
Channels
Locations
Inventory
Transport
Government
Compliance
Decision
Support
Communications
Increase Human
Productivity
Improve
Process
Reduce
Waste
Increase
Quality
Increase
Speed
Increase
SpeedIncrease
Quality
Reduce
Waste
Channel
LengthStorage
Scheduling
Info
Purchasing
Power
Cost
Engineering
Scale
Economics
Sales
Increase
Need
Territory
Management
Product
Lines
Segment
Market
Increase
Present Use
Increase
Perceived
Need
Invent
New Uses
Promotion
Increase
Companion
Products Use
Invent
New Uses
Demographic
Eliminate
Competition
Geographic
Perceived
Feature/Function
Reduce
Supply
Decrease
Price
Perceived
Price
Brand
Promotion
Packaging
Joint
Venture
Style
Franchising
Acquisition
Merge Acquire
Product
Price
Introduce
New Product
Increase
Market
Share
New
Industry Current
Industry
Compliment
Substitute
New
Product
New
Product
Substitute
Compliment
Impair
Competition
Existing
Potential
entry/exit
barriers
Market
Power
Scale
Economics
Volumes Learning
Curves
Vertical
Supplier
Power
Buyer
Power
Horizontal
Pre-emptive
Strike
Buyout
Competition
Increase Net Revenue
Figure 1 - Strategic Fishbone
Adapted from Nolan,
Norton & Company
(Bold Type indicates significance)
20. 2. Determine the Main Causes
Reports not
printed within
timeframe
Materials
Machinery
Manpower
Methodology
21. 3. Determine the Minor Causes
Reports
not
printed
within
time-
frame
Materials
Machinery
Manpower
Methodology
Insufficient
supplies
Not
enough
funds
Manpower shortage
No training
Poor proof-reading
Bad attitude
Power supply
interruptions
Insufficient
machines
Frequent breakdowns
Report received late
Late proof-reading/setting
Changes during processing
22. 4. Determine the Actual Causes
Reports
not
printed
within
time-
frame
Materials
Machinery
Manpower
Methodology
Insufficient
supplies
NOT
ENOUGH
FUNDS
Manpower shortage
No training
POOR PROOF-
READING
Bad attitude
Power supply
interruptions
Insufficient
machines
FREQUENT
BREAKDOWNS
Report received late
LATE PROOF-READING/SETTING
Changes during processing
23. 5. Arrange Causes According to Priority
Reports
not
printed
within
time-
frame
Materials
Machinery
Manpower
Methodology
Poor
proof-
reading
Frequent
break-
downs
Late proof-
reading/
setting
Not
enough
funds