Revised 21 Fishbone Diagram - PDF by pram542

VIEWS: 0 PAGES: 15

									                                 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.
☺ Advantages
  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.




                                                Further Readings

                    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.



                                  High 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.


                                High caliper discard




                                                          burrs on
                                                          calipers

                                                           many
                                                           Too




         Phase 2

                                 High caliper discard


                    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”
                              connected to its head).
                                 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

                                                     High caliper discard


                     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
                                                  caliper discard.
           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.



                                                         High caliper discard


                     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
                                   Date of creation
                                   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

								
To top