QM 07 ToolsOfQuality

©2004 Prentice-Hall

S. Thomas Foster, Jr.

Boise State University

PowerPoint

prepared by

Dave Magee

University of Kentucky

Lexington Community College

Chapter 10

The Tools of Quality

Slide 10-2 © 2004 Prentice-Hall Managing Quality: An Integrative Approach; 2nd Edition

Chapter Overview

• Improving the System

• The Plan-Do-Check-Act-Cycle

• Ishikawa’s Basic Tools of Quality

• The Seven New Tools for Improvement


Improving the System Slide 1 of 2

• Objective of the System

– To be successful, an organization must balance the

needs of its different functional areas around a coherent

business vision and strategy.

– The objective of the system is to satisfy the customer.

• Purpose of the Chapter

– In this chapter we introduce the basic seven tools of

quality, and the new seven tools.


Improving the System Slide 2 of 2

Quality System Model

Customer

Technology

Procedures

Legal

requirements

R & D People

Plant &

equipment


The Plan-Do-Check-Act Cycle Slide 1 of 2

• Plan phase

– involves identifying problems to be solved,

gathering data, doing data analysis, and

developing recommendations.

• Do phase

– involves implementing the solution on a trial

basis.


The Plan-Do-Check-Act Cycle Slide 2 of 2

• Check

– consists of a post-implementation study to ascertain whether or not the implementation resulted in the expected outcome.

• Act

– involves either adjusting the original implementation because of problems resulting from the changed or making the changes permanent if the implementation was effecting in making improvements.


Logical Order for B7 Tools

Flow

Chart

Check

Sheet Histograms

Scatter

Diagrams

Control

Charts

Cause

&

Effect

Pareto

Analysis

Big

Picture

Data

Collection

Data

Analysis

Problem

Identification Priortization

Figure 10.2


Ishikawa’s Basic Tools of Quality (B7)

Histogram

Pareto Charts

Cause & Effect

Diagrams

Check Sheets

Scatter

Diagrams

Flowcharts

Control Charts


Flowcharts Slide 1 of 7

• Flowcharts

– A flowchart is a picture of a process.

– The first step in many process improvement projects is to

flowchart the process as it exists. This useful step also

determines the parameters for process improvement. The

concept is that we must know the process before we can

improve it.



Basic Flowcharting Symbols Figure 10.3



• Simple Rules for Flowcharting

– Chart the process from the beginning, with all arcs in the

flowchart leaving and entering a symbol. The arcs

represent the progression from one step to the next.

– Develop a general process flowchart and then fill it out

by adding more detail about each of the elements.

– Step through the process by interviewing those who

perform it – as they do their work.

– Determine which steps add value and which don’t in an

effort to simplify the work.

– Before simplifying work, determine whether the work

really needs to be done in the first place.



• Example of a Flowchart

– The flowcharts on the next two slides demonstrate the

evaluation of a simple process used in the planning

department of the City of Boise, Idaho, to issue permits

allowing applicants to take possession of newly built

homes. Figure 10.4 shows the process as it existed.

– In Figure 10.5 the process was simplified as the front

desk was given more authority and training to process the

forms without assigning them for analyst review. It was

found that the analyst review did not add value for the

organization or the customer. Therefore, it was

eliminated.



Process Flowcharting: Home Occupation Process - Current

Figure 10.4



Process Flowcharting: Home Occupation Process - Proposed

Figure 10.5



• Steps in Flowcharting Include

– Settle on a standard set of flowcharting symbols to be

used.

– Clearly communicate the purpose of the flowcharting to

all the individuals involved in the flowcharting exercise.

– Observe the work being performed by shadowing the

workers performing the work.

– Develop a flowchart of the process.

– Review the flowchart with employees to make needed

changes and adjustments to the flowchart.


Check Sheets Slide 1 of 2

• Check Sheets

– Are data gathering tools that can be used in forming

histograms; they can be either tabular or schematic.

• Setting Up a Check Sheet

– Identify common defects occurring in the process.

– Draw a table with common defects in the left column and

time period across the tops of the columns to track the

defects.

– The user of the check sheet then places check marks on

the sheet whenever the defect is encountered.


Check Sheets Slide 2 of 2

Copier Problem Check Sheet Figure 10.10


Histograms Slide 1 of 3

• Histograms

– A representation of data in a bar chart format.

• Rules for Developing a Histogram

– The width of the histogram bars must be consistent

(i.e., class widths are the same where each bar contains

a single class)

– The classes must be mutually exclusive and all

inclusive.



• Number of Classes (Categories) in a Histogram

– A good rule of thumb for the number of classes is given by the model

2k n where n is the number of raw data values and k is the number of classes.

Solving for k, we obtain k is greater or equal to log n/log 2

Using this formula we find:

Number of Observations Number of Classes

9 to 16 4

17 to 32 5

33 to 64 6

65 to 128 7

129 to 256 8



Histogram of the Number of Maintenance Occurrences

and Service Hours for Four Production Lines

Figure 10.11


Scatter Diagrams Slide 1 of 3

• Scatter Diagram

– The scatter diagram or scatter plot is used to examine the

relationships between variables.

– These relationships are sometimes used to identify

indicator variables in organizations.



• Steps in Setting Up a Scatter Plot

– Determine your X (independent) and Y (dependent)

variables.

– Gather process data relating to the variables identified in

step 1.

– Plot the data on a two-dimensional Cartesian plane.

– Observe the plotted data to see whether there is a

relationship between the variables.



Prevention in Costs and Conformance Figure 10.13


Control Charts

• Control Charts

– Control charts are used to determine whether a process

will produce a product or service with consistent

measurable properties.

– Control charts are discussed in detail in Chapters 12 and

13.


Cause and Effect Diagrams Slide 1 of 4

• Cause and Effect (or Fishbone or Ishikawa)

Diagram

– A diagram designed to help workers focus on the

causes of a problem rather than the symptoms.

– The diagram looks like the skeleton of a fish, with the

problem being the head of the fish, major causes being

the “ribs” of the fish and subcauses forming smaller

“bones” off the ribs.



• Steps for Creating a Cause & Effect Diagram

a State the problem clearly in the head of the fish.

b Draw the backbone and ribs. Ask the participants in the

brainstorming session to identify major causes of the

problem labeled in the head of the diagram. If

participants have trouble identifying major problem

categories, it may be helpful to use materials, machines,

people, and methods as possible bones.



• Steps for Creating a Cause & Effect Diagram

(continued)

c Continue to fill out the fishbone diagram, asking “why?”

about each problem or cause of a problem until the fish is

filled out. Usually it takes no more than five levels of

questioning to get to root causes – hence, the “five

whys.”

d View the diagram and identify core causes.

e Set goals to address the core causes.



Cause-and Effect Diagram:

Wobbling Saw Blade Example

Figure 10.16


Pareto Charts Slide 1 of 3

• Pareto Charts

– Used to identify and prioritize problems to be solved.

– Histograms aided by the 80/20 rule adapted by Joseph

Juran from Vilfredo Pareto.

– The 80/20 rule states that roughly 80% of the problems

are caused by roughly 20% of the causes.

– This means that there are a vital few causes that create

most of the problems.



• Rules for Constructing Pareto Charts

– Information must be selected based on types or

classifications of defects that occur as a result of a

process.

– Data must be collected and classified into categories.

– A histogram or frequency chart is constructed showing

the number of occurrences.

• Steps Used in Pareto Analysis:

– Gathering categorical data relating to quality problems.

– Drawing a histogram of the data.

– Focusing on the tallest bars in the histogram first when

solving the problem.



Pareto Analysis Figure 10.18


The Seven New Tools for Improvement

Slide 1 of 3

• New Seven Tools

– In addition to the basic seven tools of quality is another

set of tools that focus on group processes and decision

making.

– The new seven tools (N7) were developed as a result of a

research effort by a committee of the Japanese Society for

QC Technique Development.



Slide 2 of 3

Affinity Diagram

The

Interrelationshiip

Digraph

Tree Diagrams

Prioritization Grid

Process Decision

Program Chart

Activity Network

Diagram

Matrix Diagram



Slide 3 of 3

Seven Management and Planning Tools Typical Flow

Affinity diagram Interrelationship

digraph

Tree diagram/

systems flow

Prioritization

matrices Matrix diagram

PDPC Activity network

diagram

Creative Logical

Unknown Known

Figure 10.21


The Affinity Diagram Slide 1 of 5

• The Affinity Diagram

– A tool that is used to help groups identify all of the issues

associated with a particular problem and converge on a

set number of themes or ideas that can be addressed later.

– An affinity diagram creates a hierarchy of ideas on a

large surface as shown in the next slide.



Affinity Diagram Figure 10.22



• Steps Used in Establishing an Affinity Diagram

1 Identify the problem to be tested. Create a clear, concise

statement of the issues that is understood by everyone.

2 Give the team members a supply of note cards and a pen.

Ask them to write down issues that relate to the problem.

There should only be one idea per card. Ask them to use

at least four or five words to clearly explain their

thinking.

3 Allow only about 10 minutes for this writing activity.

4 Place the written cards on a flat surface.

5 Lay out the finished cards so that all participants can see

and have access to all the cards.




(continued)

6 Let everyone on the team work to move the cards into

groups with a similar theme. Do this work silently

because it does not help to discuss your thinking. Work

and move quickly.

7 If you disagree with someone else’s placement of a note

card, say nothing but move it.




(continued)

8 You reach consensus when all of the cards are in groups

and the team members have stopped moving the cards.

Once consensus has been reached concerning placement

of the cards, you can create header cards.

9 Draw a finished affinity diagram and provide a working

copy for all participants.


The Interrelationship Digraph Slide 1 of 4

• Interrelationship Digraph

– A tool designed to help identify and understand the

causal relationships between the different issues that

surfaced while completing the Affinity Diagram.

– This tool also helps to identify the most important issues

to be focused on in pursuing the solution to a problem.



Interrelationship Digraph Figure 10.24



• Steps for Completing an Interrelationship Digraph

1 Construct an affinity diagram to identify the issues

relating to the problem. After you have done this, place

the cards with related issues in columns with gaps

between the cards. It is helpful to use sticky notes on a

large piece of flipchart paper.

2 Create the digraph by examining the cards one by one

asking, “What other issues on this digraph are caused or

influenced by this issue?” As team members identify

issues that are related, draw a one-way arrow from the

first issue (the cause) to the second issue (the one

influenced by the cause). Do this until all the issues have

been discussed.



• Steps for Completing an Interrelationship Digraph

(continued)

3 After reviewing the arrows and making needed revisions,

count the number of arrows pointing to each note and

write the numbers on the notes.

4 Identify the cards with the most arrows as the “key

factors.” There should not be more than 5 to 10 key

factors. Boxes with the most outgoing arrows tend to be

root causes. Boxes with incoming arrows tend to be

performance indicators.

5 Draw a double box around the key factors and brainstorm

ways to address these issues.


Tree Diagrams Slide 1 of 3

• Tree Diagrams

– A tool used to identify the steps needed to address a

particular problem.

– Very similar to a work breakdown structure used in

planning projects.



Tree Diagram Figure 10.26



• Steps Used to Complete a Tree Diagram

1 Assemble the header cards from the affinity diagram.

From these cards, choose the header card that represents

the most important issue.

2 Once the goal statement has been determined, ask, “What

are the steps required to resolve or achieve this major

objective or goal?”

3 One the major tasks have been identified, move to the

next level under each task and ask for the second level

tasks, “What are the steps required to resolve or achieve

this objective or goal?”

4 Continue doing this for successive levels until you have

exhausted your ideas for steps.


Prioritization Grid Slide 1 of 4

• Prioritization Grid

– A prioritization grid is used to make decisions based on

multiple criteria. For example, in choosing a technology,

we might have a variety of options. Also, the decision

criteria vary as to how to choose possible desired

outcomes.

– When there are multiple alternatives and multiple criteria,

a prioritization matrix is a good method to inform your

decision making without resorting to more sophisticated

analysis.



Prioritization Grid Figure 10.27



• Steps Required to Make a Prioritization Grid

1 Determine your goal, your alternatives, and the criteria by

which a decision is to be made.

2 Place the selection criteria in order from most important

to least important.

3 Apply a percentage weight to each of the criteria for each

option. Apply a weight to each of the criteria such that

all the weights add up to 1 (for example, A = .40, B = .30,

C = .25, and D = .05).

4 Sum the individual rating for each criterion to come to an

overall ranking. Divide by the number of individuals to

find an average ranking.



• Steps Required to Make a Prioritization Grid

5 Rank order each alternative with respect to the criteria.

Average the rankings and apply a completed ranking.

6 Multiply the criteria weight by it associated criterion rank

for each criterion in the matrix. Notice that in this case, a

ranking of 4 is best and 1 is worst. The result in each cell

of the matrix is called an importance score.

7 Sum the importance scores for each alternative.

8 Rank order the alternatives according to importance.


Matrix Diagram Slide 1 of 3

• Matrix Diagram

– Brainstorming tool that can be used in a group to show

the relationships between ideas or issues.

– Similar in concept to quality function deployment in its

use of symbols, its layout, and its application.

– Simple to use.

– Can be used in 2, 3 or 4 dimensions.

– Can be used to show responsibility among different

people.



Matrix Diagram Figure 10.28



• Steps for Completing a Matrix Diagram

1 Determine the number of issues or dimensions to be used

in the matrix.

2 Choose the appropriate matrix.

3 Place the appropriate symbols in the matrix.


Process Decision Program Chart Slide 1 of 4

• Process Decision Program Chart

– A tool to help brainstorm possible contingencies or

problems associated with the implementation of some

program or improvement.

• Example of a Process Decision Program Chart

– An example of a process decision control chart in tree

form is shown on the next slide.



Process Decision Program Chart Figure 10.30



• Steps in Completing a Process Decision Program

Chart

1 In developing the tree diagram, place the first-level boxes

in sequential order. (These are the boxes in the first

column in the example.)

2 Moving to the second level, list implementation details at

a fairly high level. Try to be all-inclusive at a

macrolevel.

3 At the third level, ask the question, “What unexpected

things could happen in this implementation?” or “What

could go wrong at this stage?”



• Steps in Completing a Process Decision Program

Chart (continued)

4 At the fourth level, brainstorm possible countermeasures

to the problems identified at the third level.

5 Evaluate the counter measures for feasibility and mark

those that are feasible with an O and those that are not

feasible with an X.


Activity Network Diagram Slide 1 of 2

• Activity Network Diagram

– An activity network diagram is also known as a PERT

(program evaluation and review technique) diagram or

critical path (longest path in time from beginning to end)

diagram and is used in controlling projects.

– These are discussed in detail in Chapter 11.

• Example of an PERT Diagram

– The figure on the next slide shows a PERT diagram with

nodes and times. The nodes are circles and the times are

given in days.


Activity Network Diagram Slide 2 of 2

Activity Network Diagram Figure 10.31


Summary

• Improving the System

• The Plan-Do-Check-Act-Cycle

• Ishikawa’s Basic Tools of Quality

• The Seven New Tools for Improvement

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