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```									                                 Data Analysis
Core Competencies

15   Data Analysis Techniques

16   Descriptive Statistics

17   Inf erential Statistics

18   Graphing Data

19   Aff inity Diagram

20   Delphi Technique

21   Fishbone (Cause-and-Effect)Diagram
22   Force Field Analysis

23   Pareto Diagram

EMRA, 1998
PART 4 : Data Analys is Core Com petenc ies
Section 21:                 Fis hbone (Cause-a nd-Effect) Diagram
CONTENTS

Overview                                             PAGE           Steps a nd Proce dures                                   PAGE

Introduction                                            3           1    Assemble a Team to Carry Out the
Figure 1: Basic Structure of a Fishbone Diagram                          Diagramming Process                                      7
Figure 2: Categorical Patterns for a T ypical
Production Process

2    Identify and Clearly State the Need                      7
Purposes of Fishbone Diagram                            3                Figure 4: Affinity Diagram Example

Advantages and Limitations of                                       3    Draw the Structure of a Fishbone
Fishbone Diagram                                        5
Figure 3: Advantages and Limitations of
Diagram                                                  9
Fishbone Diagram                                               Figure 5: Fishbone Diagram Example
(Phases 1 and 2)

4    Identify Major Cause Categories and
Connect Them to the Backbone of
the Fish                                                 9

5    Brainstorm Causes for Each of the
Major Categories                                         11

6    Place Each Brainstormed Cause in
Its Appropriate Category                                 11
Figure 6: Fishbone Diagram Example (Phase 3)

7    Identify Potential Root Causes                           11

8    General Discussion of the Fishbone
Diagram                                                  13
Figure 7: Fishbone Diagram Completed Example
(Phase 4)

9    Logistical and Follow-Up Activities                      13
Legend:

☺
Key Poi nts an d Ideas
Refer enc es to
parts of the han d-   Important points,            Adva ntag es
Refer enc e not es            book an d othe r      hints and ideas.
and s up ple ment al          ide as.
inform atio n on
opp osite pa ge.
Num ber ed
steps a nd                                        Limit atio ns
1      Proce dur es                                                                                          21 - 1
PART 4: Data Analysis Core Competencies
FISHBONE (CAUSE-AND- EFFECT) DIAGRAM

NOTES AND SUPPLEMENTAL INFORMATION

Figure 21.1: Basic Structure of a Fishbone Diagram
OVERVIEW

Cause (factors)                                Effect

Figure 21.2: Categorical Patterns for a Typical Production Process

Machine         Operator    Env ironment
production
scrap in
much
Too

Material         Method

21 - 2                                                                              EMRA, 1998
PART 4: Data Analysis Core Competencies
FISHBONE (CAUSE-AND- EFFECT) DIAGRAM

OVERVIEW

Intr oduction

The Fishbone Diagram is an easy to use and effective cause-and-effect
technique developed by Kaoru Ishikawa (1982). It is also referred to as an
“Isikawa diagram” or a “characteristics diagram”, referring to its use in
identifying the causes of various quality characteristics, including problems
Figure 21.1 shows
the basic structure of      (Ozeki & Asaka, 1990).
a Fishbone Diagram.
The late Dr. Ishikawa was a quality expert who used this diagramming
strategy to help Japanese business personnel in organizing those factors that
influence a business or manufacturing process. The diagram has a cause side
and an effect -- problem or opportunity -- side. It graphically represents the
causes of a related need or problem.

On the effect side of the diagram, the effect under analysis can be either
a current work problem that needs to be corrected or a desired quality
Figure 21.2 shows          characteristic. On the cause side of the diagram are the factors that influence
a Fishbone Diagram         the stated effect or characteristic. Categorical examples of some of the cause
with standard              factors are equipment, people, environment, materials, and procedures. The
categorical patterns
for a typical production   strength of the technique lies in using a diagram to analyze causal relationships
process.                   in structured ways focusing attention beyond symptoms to root, or primary,
causes (Swanson, 1995).

Purposes of Fis hbone Diagram

The Fishbone Diagram technique was originally developed for analyzing
the factors that influence the process of developing quality products. However,
it can be used as a tool for analyzing information related to a needs analysis
and selecting alternative interventions for performance improvement. Used in
these ways, the Fishbone Diagram will help to generate ideas about the
possible
causes of problems and identify the components in the process that are
responsible for the existing problems. It can also be used to plan new
processe s to meet quality improvement initiatives or new business
opportunities.

Typically you will see a Fishbone Diagram used in the following ways:
A Fishbone Diagram is
a useful method for                           To identify major or minor reasons for a specific problem
clarifying the causes of
a problem.
of performance.
To identify root causes, or key drivers, contributing to
some effect or measurable outcome (a performance
indicator).
To identify key causes for which additional data are
required (Swanson, 1995).

EMRA, 1998                                                                                             21 - 3
PART 4: Data Analysis Core Competencies
FISHBONE (CAUSE-AND- EFFECT) DIAGRAM

NOTES AND SUPPLEMENTAL INFORMATION

Figure 21.3: Advantages and Limitations of Fishbone Diagram*
OVERVIEW

☺                    Advantage s of Fi shbone Diagram
Fishbone Diagramming is adaptable to analyzing causes of problems in a
variety of settings. It has been used successfully in business and industry.

Groups find the method enjoyable. They can usually complete the work in
a session lasting 1 to 2 hours.

There is a strong sense of involv ement in resolv ing problems and in
ownership of results.

Facilitators need little training to implement the procedure.

No special equipment is needed.

The technique results in a graphic representation of the relationships that
exist betw een effects and their causes.

Limitations of Fi shbone Diagram
Although groups can quickly determine potential causes, Fishbone
Diagramming does not usually clarif y sequences of causes.

The magnitude and probability of a cause contributing to a need are not
established as part of the technique.

The causes identif ied require verific ation of some kind.

*Adapted from Planning and Conducting Needs Assessments by Witkin and Altschuld -- pg.. 248

21 - 4                                                                                        EMRA, 1998
PART 4: Data Analysis Core Competencies
FISHBONE (CAUSE-AND- EFFECT) DIAGRAM

OVERVIEW

Adva ntages and Lim itations of Fishbone Diagram

Identifying the primary or root causes of a problem can be difficult.
The Fishbone Diagram process is useful. It has advantages and some
limitations, and a needs analyst must be familiar with these prior to employing
Fishbo ne Diagram   the technique.
Limitations
Before incorporating the information into a major needs analysis study, the
results of more than one Fishbone Diagramming analysis using different, but
comparable groups, should be made and compared in order to ensure the
validity and reliability of the results.

Arcaro, J. S. (1995). Quality in education: An implementation handbook.
Delray Beach, FL: St. Lucie.

Swanson, R. C. (1995). The quality improvement handbook: Team guide
to tools and techniques. Delray Beach, FL: St. Lucie.

Witkin, B. R., Altschuld, J. W. (1995). Planning and conducting needs
asse ssment: A practical guide. Thousand Oaks, CA: Sage.

EMRA, 1998
21 - 5
PART 4: Data Analysis Core Competencies
FISHBONE (CAUSE-AND- EFFECT) DIAGRAM

NOTES AND SUPPLEMENTAL INFORMATION

STEPS AND
PROCEDURES                 Figure 21.4: Completed Example of an Affinity Diagram

Perform ance Problem : Too many burrs on calipers resulting
in high rates of caliper discard.

Problems with    Operator          Problems           Methods
Environment         Machinery        Error              with               not
Issues              and/or                          Materials         Appropriate
Equipment

No time to       Alloy mixture      Grinder is too
Shop floor is     Old machines   practice doing     not constant            fast
too small
the job

No regular    Borrowed from                         Debur tool is
Poor use of                                         Sand forms
maintenance    other assembly                         too short to
space                                              are rough
lines                            reach inside

T ask better for    Scrap metal       Belt from the
Unreliable    a left handed
is poor quality    grinder is too
fork-lift       a worker                                fast

T ools are not       Cooling           Collection
good for the      process not         tray is too
deburring job         correct             small

No Fit                      New hires can
not ID all kinds
of burrs

Quality                        Not enough
parameters
breaks
too high

Customer                        Literacy skills
complaints                           need
improvement

21 - 6                                                                                              EMRA, 1998
PART 4: Data Analysis Core Competencies
FISHBONE (CAUSE-AND- EFFECT) DIAGRAM
STEPS AND
PROCEDURES

Using Fishbone Diagramming in Needs Analysis
It yields a cause-and-effect diagram which identifies possible causes of a
problem (need) or barriers to actualizing a business opportunity.

The structured way in which a Fishbone Diagram is developed using
categories of causes often leads to the identification of root causes.

It is a relatively easy way to take an in-depth look at an expressed need to
seek out probable causes and contributing factors.

USE THE FOLLOWING 9 STEPS TO CARRY OUT
A FISHBONE DIAGRAM

1      Assemble a Team to Carry Out the Diagramming Process

It may be useful
to review the       1-1    Identify and select team participants that:
brainstorming
guidelines on
Have expertise and experience related to the identified need
page 22.6 or                  Represent various groups and perspectives impacted by need
Section 19 on the             Are viewed as credible by managers and workers who are
Affinity Diagram.
impacted by the need being addressed

1-2    Arrange for a team meeting.
Allow up to 3 hours for each diagram to be completed

1-3    Brief the team as to the purposes of the meeting and explain the
procedures to be followed.

2     Identify and Clearly State the Need

2-1    Explain to the group how the need was identified.
Figure 21.4 shows
the output from an     2-2    Present data collected about the need from the needs analysis.
example Affinity
Use available data to specify the need
Diagram.
Identify as much as possible about the “what, where, when,
and how much” of the need

2-3    Question each team member to be certain that the need is clearly
understood by all team members.

EMRA, 1998                                                                                             21 - 7
PART 4: Data Analysis Core Competencies
FISHBONE (CAUSE-AND- EFFECT) DIAGRAM

NOTES AND SUPPLEMENTAL INFORMATION

STEPS AND
PROCEDURES          Figure 21.5: Fishbone Diagram Example (Phases 1 and 2)

Phase 1        Performance Problem: Too many burrs on calipers resulting
in high rates of caliper discard.

burrs on
calipers

many
Too

Phase 2

Machine          Operator
burrs on
calipers

many
Too

Material              Method

21 - 8                                                                          EMRA, 1998
PART 4: Data Analysis Core Competencies
FISHBONE (CAUSE-AND- EFFECT) DIAGRAM
STEPS AND
PROCEDURES

3     Draw the Structure of a Fishbone Diagram

3-1   Use flipchart sheet, butcher paper, or a large while board (paper is
preferable because the diagram can be moved and saved).

3-2   Write the need in a box at the right side of the paper (in the “head
of the fish”).

3-3   Draw a line across the middle of the paper (the “spine of the fish”
Provide enough space to diagram causal factors and their
relationships in handwriting that is legible
Diagram symmetry and the shape of the fish are NOT prime
considerations -- realistic information that is clear in meaning
and easily interpreted are the goals

Identify Major Cause Categories and Connect Them to the
4    Backbone of the Fish

4-1   Have the group list categories of factors causing the need (problem).
These will serve as headings of the major bones of the fish
Figure 21.5 presents            They should be logical and inclusive
a Fishbone Diagram
example (Phases 1
and 2).                4-2   Check the list against the following standard patterns:
Typical production process categories
Machines -- facilities and equipment
Methods -- how work gets done
Materials -- components or raw materials
People -- the human factor
Typical service process categories
Policies -- higher-level decision rules
Procedures -- steps in a task
Plant -- equipment and space
People -- the human factor
Other typical categories
Environment -- work culture, organizational structure, logistics
Measurement -- calibration and data collection
4-3   Check the fishbone diagram for omitted factors
Compare to data from the needs analysis
Use a consensus process with the group to assure
complete input by all team members

EMRA, 1998                                                                                          21 - 9
PART 4: Data Analysis Core Competencies
FISHBONE (CAUSE-AND- EFFECT) DIAGRAM

NOTES AND SUPPLEMENTAL INFORMATION

STEPS AND
PROCEDURES                                Figure 21.6: Fishbone Diagram Example (Phase 3)

Phase 3

Machine                                       Operator  P

Company Owned equi pment
oo
r
tra

U
N

nr
in

Shop floor too s mall
o

el
in
re

ia
g

P
g

oo                              bl                                       Borrowed from other
ul

e
ar

r                                 fo                                     lines temporarily
us                                rk
m

e                                -li
ai

of
nt

ft
en

sp
an

ac                                                                          Left handed
c

e
e

burrs on
calipers

many
Too
st

Debur tool too s hort
fa
oo
rt

Alloy mi x not exac t
de

Belt too fast
in
Gr

C ma
ol ll
s
le
ct
io

Material                                      Method
n
tr
a
yt
oo

:

21 -10                                                                                                                          EMRA, 1998
PART 4: Data Analysis Core Competencies
FISHBONE (CAUSE-AND- EFFECT) DIAGRAM
STEPS AND
PROCEDURES

5     Brainstorm Causes for Each of the Major Categories
5-1   Use the major cause categories as catalysts for analysis.
5-2   Ask: What in the “materials” category is causing...?
5-3   Repeat step 5-2 for each major category.
5-4   For each identified cause, ASK:
Why does it happen?
What could happen?

6    Place Each Brainstormed Cause in Its Appropriate Category

6-1   Draw as many bones, sub-bones, and sub-sub-bones as necessary to
reflect the relationships of related cause factors. Each major bone or
cause may have sub-bones and even sub-sub-bones.

6-2   Label each bone and sub-bone and draw the head of an arrow at
the end of each bone to indicate its contribution to the “bigger bone”
which it impacts.
Figure 21.6 presents a
Fishbone Diagram         6-3   List causes related to multiple bones in all appropriate locations.
example (Phase 3).
6-4   Check against the needs analysis data to be certain that all causes and
sub-causes have been identified.

6-5   Review the diagram to see if it needs restructuring -- make changes until
group consensus is reached.

7    Identify Potential Root Causes

7-1   Have the team discuss factors that strongly affect a factor.
Causes that are repeated on the diagram are often ones that
need to be analyzed further
Use additional brainstorming and review needs analysis data
and related information to verify root causes
7-2   Circle each factor that strongly affects the problem or opportunity.

7-3   Check for group consensus concerning:
The list of items that are included in the diagram which may be
causing dispersion
The proper illustration of their relationships

7-4   The diagram is complete.

EMRA, 1998                                                                                          21 -11
PART 4: Data Analysis Core Competencies
FISHBONE (CAUSE-AND- EFFECT) DIAGRAM

NOTES AND SUPPLEMENTAL INFORMATION

STEPS AND
PROCEDURES                       Figure 21.7: Fishbone Diagram Completed Example (Phase 4)

Phase 4

Perform ance Problem :                 Too many burrs on calipers resulting in high rates of
Created:                               April 2, 1998
Participants:                          Manufacturing Quality Team Plant 1:
G. Smith, R. Lee, A. Jones, S. Perkins, and F. Beck
Method:                                Brainstorming session to identify major causes of
performance problem. Data analysis using a Fishbone
Diagram process.

Machine                                      Operator
P

Company Owned equi pment
oo
r
tra
N
U

in

Shop floor too s mall
o
nr

in
re
el

g

Borrowed from other
ia

g
P

ul
bl
oo

ar
e

lines temporarily
r

fo

m
us

rk

ai
e

-li

nt
of

ft

en
s

an

Left handed
pa

c
ce

e

burrs on
calipers

many
Too
st

Debur tool too s hort
fa
oo
rt

Alloy mi x not exac t
de

Belt too fast
in
Gr

C ma
ol ll
s
le
ct
io

Material :                                    Method
n
tr
a
yt
oo

21 -12                                                                                                                           EMRA, 1998
PART 4: Data Analysis Core Competencies
FISHBONE (CAUSE-AND- EFFECT) DIAGRAM
STEPS AND
PROCEDURES

8    General Discussion of the Fishbone Diagram

8-1   Discuss the completed fishbone diagram.
Select the most important sub-factors that contribute to the
main causal factors
Suggest intervention(s) to meet the need or the business
opportunity

8-2   Have the group compare and contrast the findings reflected in the
Fishbone Diagram with their overall judgments about the need and
its causes.

9    Logistical and Follow Up Activities

Figure 21.7 presents a
9-1   Re-do the diagram to make it graphically appealing.
completed Fishbone
Diagram example          9-2   Write in information detailing:
(Phase 4).
The identification of the need
Participants
How and why it was created

9-3   If, validity and reliability are of concern:
Conduct two or three more Fishbone Diagramming sessions
with similar groups under similar circumstances
Compare and contrast the results from the multiple Fishbone
Diagram analyses

9-4   Incorporate the major causal findings from the Fishbone
Diagramming process into the findings portion of the needs
analysis report.
See Section 7 on
Reporting Results.

EMRA, 1998                                                                                       21 -13

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