basic 7 tools of quality

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Basic Seven Tools of Basic Seven Tools of QualityQuality

Slides Prepared bySlides Prepared by

Kara FagleyKara Fagley



QuickQuick OverviewOverview

The Seven ToolsThe Seven Tools

² ² Histograms, Pareto Charts, CauseHistograms, Pareto Charts, Cause

and Effect Diagrams, Run Charts,and Effect Diagrams, Run Charts,

Scatter Diagrams, Flow Charts,Scatter Diagrams, Flow Charts,

Control ChartsControl Charts



Ishikawa·s Basic Tools of Ishikawa·s Basic Tools of

QualityQuality Kaoru Ishikawa developed sevenKaoru Ishikawa developed seven

basic visual tools of quality so thatbasic visual tools of quality so that

the average person could analyzethe average person could analyzeand interpret data.and interpret data.

These tools have been usedThese tools have been used

worldwide by companies, managersworldwide by companies, managers

of all levels and employees.of all levels and employees.



HistogramsHistograms

Slide 1 of 3Slide 1 of 3

Histogram DefinedHistogram Defined

² ² A histogram is a bar graph thatA histogram is a bar graph that

shows frequency data.shows frequency data.

² ² Histograms provide the easiestHistograms provide the easiest

way to evaluate the distribution of way to evaluate the distribution of

data.data.





Creating a HistogramCreating a Histogram ² ² Collect data and sort it into categories.Collect data and sort it into categories.

² ² Then label the data as the independentThen label the data as the independentset or the dependent set.set or the dependent set.

The characteristic you grouped the data byThe characteristic you grouped the data bywould be the independent variable.would be the independent variable.

The frequency of that set would be theThe frequency of that set would be the

dependent variable.dependent variable. ² ² Each mark on either axis should be inEach mark on either axis should be in

equal increments.equal increments.

² ² For each category, find the relatedFor each category, find the relatedfrequency and make the horizontal marksfrequency and make the horizontal marks

to show that frequency.to show that frequency.





Examples of How HistogramsExamples of How Histograms

Can Be UsedCan Be Used

² ² Histograms can be used toHistograms can be used to

determine distribution of sales.determine distribution of sales.

² ² Say for instance a companySay for instance a company

wanted to measure the revenues of wanted to measure the revenues of other companies and wanted toother companies and wanted to

compare numbers.compare numbers.



Pareto ChartsPareto Charts


Pareto Chart DefinedPareto Chart Defined

² ² Pareto charts are used to identify andPareto charts are used to identify and

prioritize problems to be solved.prioritize problems to be solved. ² ² They are actually histograms aided byThey are actually histograms aided by

the 80/20 rule adapted by Joseph Juran.the 80/20 rule adapted by Joseph Juran.

Remember the 80/20 rule states thatRemember the 80/20 rule states that

approximately 80% of the problems areapproximately 80% of the problems are

created by approximately 20% of the causes.created by approximately 20% of the causes.





Constructing a Pareto ChartConstructing a Pareto Chart

² ² First, information must be selectedFirst, information must be selected

based on types or classifications of based on types or classifications of defects that occur as a result of adefects that occur as a result of aprocess.process.

² ² The data must be collected andThe data must be collected andclassified into categories.classified into categories.

² ² Then a histogram or frequency chartThen a histogram or frequency chartis constructed showing the number of is constructed showing the number of occurrences.occurrences.





An Example of How a Pareto ChartAn Example of How a Pareto ChartCan Be UsedCan Be Used

² ² Pareto Charts are used when products arePareto Charts are used when products aresuffering from different defects but the defectssuffering from different defects but the defectsare occurring at a different frequency, or only aare occurring at a different frequency, or only afew account for most of the defects present, or few account for most of the defects present, or different defects incur different costs. What wedifferent defects incur different costs. What wesee from that is a product line may experience asee from that is a product line may experience arange of defects. The manufacturer couldrange of defects. The manufacturer couldconcentrate on reducing the defects which makeconcentrate on reducing the defects which makeup a bigger percentage of all the defects or focusup a bigger percentage of all the defects or focuson eliminating the defect that causes monetaryon eliminating the defect that causes monetaryloss.loss.

Actual chart is on the next slideActual chart is on the next slide»» Example and chart were obtained from:Example and chart were obtained from:

<www.yourmba.co.uk/pareto_diagram.htm><www.yourmba.co.uk/pareto_diagram.htm>



Cause and Effect DiagramsCause and Effect Diagrams


Cause and Effect DiagramCause and Effect Diagram

DefinedDefined ² ² The cause and effect diagram is also called theThe cause and effect diagram is also called the

Ishikawa diagram or the fishbone diagram.Ishikawa diagram or the fishbone diagram.

² ² It is a tool for discovering all the possible causesIt is a tool for discovering all the possible causes

for a particular effect.for a particular effect.

² ² The major purpose of this diagram is to act as aThe major purpose of this diagram is to act as a

first step in problem solving by creating a list of first step in problem solving by creating a list of possible causes.possible causes.





Constructing a Cause and EffectConstructing a Cause and EffectDiagramDiagram

² ² First, clearly identify and define the problem or First, clearly identify and define the problem or effect for which the causes must be identified.effect for which the causes must be identified.Place the problem or effect at the right or thePlace the problem or effect at the right or thehead of the diagram.head of the diagram.

² ² Identify all the broad areas of the problem.Identify all the broad areas of the problem.

² ² Write in all the detailed possible causes in eachWrite in all the detailed possible causes in each

of the broad areas.of the broad areas. ² ² Each cause identified should be looked upon for Each cause identified should be looked upon for

further more specific causes.further more specific causes.

² ² View the diagram and evaluate the main causes.View the diagram and evaluate the main causes.

² ² Set goals and take action on the main causes.Set goals and take action on the main causes.





An Example of When a Cause andAn Example of When a Cause andEffect Diagram Can Be UsedEffect Diagram Can Be Used

² ² This diagram can be used to detect theThis diagram can be used to detect theproblem of incorrect deliveries.problem of incorrect deliveries. Diagram on next slideDiagram on next slide

² ² Diagram obtained from:Diagram obtained from:<http://www.hci.com.au/hcisite/toolkit/causeand<http://www.hci.com.au/hcisite/toolkit/causeand.htm>.htm>

² ² When a production team is about toWhen a production team is about tolaunch a new product, the factors thatlaunch a new product, the factors thatwill affect the final product must bewill affect the final product must berecognized. The fishbone diagram canrecognized. The fishbone diagram candepict problems before they have adepict problems before they have a

chance to begin.chance to begin.





Diagram of the Incorrect Deliveries Example:Diagram of the Incorrect Deliveries Example:



Scatter DiagramsScatter Diagrams


Scatter Diagrams DefinedScatter Diagrams Defined

² ² Scatter Diagrams are used to studyScatter Diagrams are used to study

and identify the possibleand identify the possiblerelationship between the changesrelationship between the changes

observed in two different sets of observed in two different sets of

variables.variables.





Constructing a Scatter DiagramConstructing a Scatter Diagram

² ² First, collect two pieces of data andFirst, collect two pieces of data and

create a summary table of the data.create a summary table of the data. ² ² Draw a diagram labeling theDraw a diagram labeling the

horizontal and vertical axes.horizontal and vertical axes. It is common that the ćauseµ variable beIt is common that the ćauseµ variable be

labeled on the X axis and the éffectµ variablelabeled on the X axis and the éffectµ variable

be labeled on the Y axis.be labeled on the Y axis. ² ² Plot the data pairs on the diagram.Plot the data pairs on the diagram.

² ² Interpret the scatter diagram for Interpret the scatter diagram for direction and strength.direction and strength.





An Example of When a Scatter An Example of When a Scatter

Diagram Can Be UsedDiagram Can Be Used

² ² A scatter diagram can be used toA scatter diagram can be used to

identify the relationship betweenidentify the relationship between

the production speed of anthe production speed of an

operation and the number of operation and the number of

defective parts made.defective parts made.





An Example of When a Scatter An Example of When a Scatter Diagram Can Be Used (cont.)Diagram Can Be Used (cont.)

² ² Displaying the direction of theDisplaying the direction of therelationship will determine whether relationship will determine whether increasing the assembly line speed willincreasing the assembly line speed willincrease or decrease the number of increase or decrease the number of defective parts made. Also, the strengthdefective parts made. Also, the strength

of the relationship between the assemblyof the relationship between the assemblyline speed and the number of defectiveline speed and the number of defectiveparts produced is determined.parts produced is determined.

² ² Example obtained from:Example obtained from:<http://www.sytsma.com/tqmtools/Scat.html><http://www.sytsma.com/tqmtools/Scat.html>



Flow ChartsFlow Charts


Flow Charts DefinedFlow Charts Defined

² ² A flow chart is a pictorialA flow chart is a pictorial

representation showing all of therepresentation showing all of thesteps of a process.steps of a process.





Creating a Flow ChartCreating a Flow Chart

² ² First, familiarize the participants withFirst, familiarize the participants with

the flow chart symbols.the flow chart symbols. ² ² Draw the process flow chart and fill itDraw the process flow chart and fill it

out in detail about each element.out in detail about each element.

² ² Analyze the flow chart. Determine whichAnalyze the flow chart. Determine which

steps add value and which don·t in thesteps add value and which don·t in theprocess of simplifying the work.process of simplifying the work.





Examples of When to Use a FlowExamples of When to Use a Flow

ChartChart

² ² Two separate stages of a processTwo separate stages of a process

flow chart should be considered:flow chart should be considered:

The making of the productThe making of the product

The finished productThe finished product



Run ChartsRun Charts


Run Charts DefinedRun Charts Defined

² ² Run charts are used to analyzeRun charts are used to analyze

processes according to time or processes according to time or order.order.





Creating a Run ChartCreating a Run Chart ² ² Gathering DataGathering Data

Some type of process or operation must beSome type of process or operation must beavailable to take measurements for analysis.available to take measurements for analysis.

² ² Organizing DataOrganizing Data Data must be divided into two sets of values XData must be divided into two sets of values X

and Y. X values represent time and values of Yand Y. X values represent time and values of Yrepresent the measurements taken from therepresent the measurements taken from themanufacturing process or operation.manufacturing process or operation.

² ² Charting DataCharting Data Plot the Y values versus the X values.Plot the Y values versus the X values.

² ² Interpreting DataInterpreting Data Interpret the data and draw any conclusions thatInterpret the data and draw any conclusions that

will be beneficial to the process or operation.will be beneficial to the process or operation.





An Example of Using a Run ChartAn Example of Using a Run Chart

² ² An organization·s desire is to have their An organization·s desire is to have their

product arrive to their customers on time,product arrive to their customers on time,but they have noticed that it doesn·t take thebut they have noticed that it doesn·t take the

same amount of time each day of the week.same amount of time each day of the week.

They decided to monitor the amount of timeThey decided to monitor the amount of time

it takes to deliver their product over the nextit takes to deliver their product over the next

few weeks.few weeks.





Control Charts DefinedControl Charts Defined

² ² Control charts are used toControl charts are used to

determine whether a process willdetermine whether a process willproduce a product or service withproduce a product or service with

consistent measurable properties.consistent measurable properties.





Steps Used in Developing ProcessSteps Used in Developing ProcessControl ChartsControl Charts

² ² Identify critical operations in the processIdentify critical operations in the processwhere inspection might be needed.where inspection might be needed.

² ² Identify critical product characteristics.Identify critical product characteristics.

² ² Determine whether the critical productDetermine whether the critical productcharacteristic is a variable or ancharacteristic is a variable or an

attribute.attribute. ² ² Select the appropriate process controlSelect the appropriate process control

chart.chart.

² ² Establish the control limits and use theEstablish the control limits and use thechart to monitor and improve.chart to monitor and improve.

² ² Update the limits.Update the limits.





An Example of When to Use aAn Example of When to Use a

Control ChartControl Chart

² ² Counting the number of defectiveCounting the number of defective

products or servicesproducts or services

Do you count the number of defects inDo you count the number of defects in

a given product or service?a given product or service?

Is the number of units checked or Is the number of units checked or

tested constant?tested constant?



ActivityActivity Process Flow Chart for Finding theProcess Flow Chart for Finding the

Best Way HomeBest Way Home

² ² Construct a process flow chart byConstruct a process flow chart bymaking the best decisions in finding themaking the best decisions in finding thebest route home.best route home.

² ² Refer to the prior notes on flowcharts.Refer to the prior notes on flowcharts. Remember: Define and analyze the process,Remember: Define and analyze the process,

build a stepbuild a step--by step picture of the process,by step picture of the process,and define areas of improvement in theand define areas of improvement in theprocess.process.

»» Answer is on the next slideAnswer is on the next slide

»» Example obtained from:Example obtained from:<http://deming.eng.clemson.edu/pub/tutorial<http://deming.eng.clemson.edu/pub/tutorials/qctools/flowm.htm#Example>s/qctools/flowm.htm#Example>



SummarySummaryThis presentation provided learningThis presentation provided learningmaterial for each of Ishikawa·s seven basicmaterial for each of Ishikawa·s seven basictools of quality.tools of quality.

Each tool was clearly defined withEach tool was clearly defined withdefinitions, a stepdefinitions, a step--byby--step process and anstep process and anexample of how the tool can be used.example of how the tool can be used.

As seen through the presentation, theseAs seen through the presentation, thesetools are rather simple and effective.tools are rather simple and effective.



WorksWorks -- SitedSited Histograms and Bar Graphs.Histograms and Bar Graphs.

<http://www.shodor.org/interactivate/lessons/sm3.html><http://www.shodor.org/interactivate/lessons/sm3.html>

Your MBA: The Business Study Reference Site.Your MBA: The Business Study Reference Site.http://yourmba.co.uk/pareto_diagram.htmhttp://yourmba.co.uk/pareto_diagram.htm

Hci Home Services. Cause and Effect Diagram.Hci Home Services. Cause and Effect Diagram.http://hci.com.au/hcisite/toolkit/causeand.htmhttp://hci.com.au/hcisite/toolkit/causeand.htm

Scatter Diagram.Scatter Diagram. http://sytsma.com/tqmtools/Scat.htmlhttp://sytsma.com/tqmtools/Scat.html

Flowchart.Flowchart.<http://http://deming.eng.clemson.edu/pub/tutorials/qctools<http://http://deming.eng.clemson.edu/pub/tutorials/qctools/flowm.htm>/flowm.htm>

Run Charts/Time Plot/ Trend Chart.Run Charts/Time Plot/ Trend Chart.<http://www.deming.edu.clemson.edu/pub/tutorials/qctool<http://www.deming.edu.clemson.edu/pub/tutorials/qctools/runm.htm>s/runm.htm>

Foster Thomas S.Foster Thomas S. Managing Quality An IntegrativeManaging Quality An IntegrativeApproachApproach. New Jersey: Prentice Hall, 2001. New Jersey: Prentice Hall, 2001

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