3g and 7 qc tools
TRANSCRIPT
3 G’ s3 G’ s
GENCHI : ACTUAL PLACE
GENBUTSU: ACTUAL THING
GENJITSU: ACTUALLY
QC TOOLSQC TOOLS
QC Tools are based on statistical methods
and are effective for improving the production process and reducing its defects.
The first step in finding the true cause is careful observation of the phenomenon of the defect. After such careful observation, the true cause becomes apparent.
Analyzing Problems Using DataAnalyzing Problems Using Data
Objective of Collecting DataData is a guide for our actions. From data we
learn pertinent facts which are useful for problem solving.
Data is required for controlling and monitoring the process
Data is required for analysis of non-conformance
QC TOOLSQC TOOLS
Whenever a problem occurs: Urgently proceed to the workplace where the fault has occurred. Ascertain the fault visually. Observe well the conditions leading to the fault.Listen attentively to the opinion of the operator.
QC TOOLSQC TOOLS
QC tools lend objectivity and accuracy to observation. The principles of statistical way of thinking are: Give greater importance to facts. Do not express facts in terms of senses or ideas. Use figures derived from specific observed results. Go to the actual site where problem is occurring, observe the actual object, and make measurements on that object actually by yourself.
QC TOOLSQC TOOLS
Observational results, accompanied as they are by error and variation, are part of a hidden whole. Finding that hidden whole is observation’s ultimate goal.
Accept regular tendency, which appears in a large number of observational results as a reliable information.
QC TOOLSQC TOOLS
Seven QC Tools are useful for analyzing problems using data. These seven tools are:
Check Sheet Histogram
Scatter Diagram Graphs
Pareto Diagram
Cause and Effect Diagram
Control Charts
CHECK SHEETSCHECK SHEETS
SIMPLIFYING DATA COLLECTIONENSURES THAT NO ITEMS ARE OMITTED
WHEN INSPECTINGSTARTING POINT FOR PROBLEM
SOLVINGUSEFUL FOR PROCESS CONTROL
CHECK SHEETSCHECK SHEETS
Check Sheet
Product: Date:
No. Inspected Lot no.
Inspector’s name
Type of defect Number of Total
Cracks
Scratch
Blowholes
Dimension
Surface finish
7
HISTOGRAMSHISTOGRAMS
PLOTTING THE SHAPE OF A DISTRIBUTION
COMPARING THE DISTRIBUTION WITH SPECIFICATIONS
USEFUL FOR QUALITY, COST AND DELIVERY IMPROVEMENT
USEFUL FOR PROCESS CONTROL
HistogramsHistograms
Histogram
LSLUSL
Diameter
Frequency
SCATTER DIAGRAMSSCATTER DIAGRAMSEXAMPLES:
POSITIVE CORRELATION -
OVERTIME VS ERRORS
HEIGHT VS WEIGHT
NEGATIVE CORRELATION-
EXTERNAL TEMPERATURE VS GAS BILL
QUALITY VS CUSTOMER COMPLAINTS
NO CORRELATION
HEIGHT VS MARKS IN BOARD EXAMS
Scatter DiagramsScatter Diagrams
Scatter Diagram
Temperature
% defective
. .
…
..
…
.
. .
. .
.. .. .. .. ..
.. .. .. .. .. . . .. ....
NegativeCorrelation
Zero correlation
PositiveCorrelation
PARETO CHARTPARETO CHARTBAR CHARTRANKS PROBLEMS IN DESCENDING ORDER OF COST OF FREQUENCY
SEPARATES “VITAL FEW” FROM THE “USEFUL MANY”
SINGLES OUT THE REALLY SERIOUS PROBLEMS FROM AMONG ALL THE LESSER ONES
HIGHLIGHTS WHERE YOUR PROBLEM SOLVING ACTIVITY WILL MAKE THE GREATEST IMPACT.
PARETO CHARTPARETO CHART
Pareto Diagram
No.Of
ProblemItems
Problem Type
CumulativePercentage
CAUSE AND EFFECT CAUSE AND EFFECT DIAGRAMSDIAGRAMS
DESIGNED TO REPRESENT A MEANINGFUL RELATIONSHIP BETWEEN AN EFFECT AND ALL ITS POSSIBLE CAUSES.
PICKING UP AND ARRANGING ALL POSSIBLE CAUSES WITHOUT ANY OMISSIONS
USED TO INVESTIGATE DEFECT CAUSE AS WELL AS TO INVESTIGATE AN IN-CONTROL PROCESS
ALSO KNOWN AS FISH BONE OR ISHIKAWA DIAGRAM.
CAUSE AND EFFECT CAUSE AND EFFECT DIAGRAMSDIAGRAMS
Main bone
Problem or
Effect
Man Machine
Material MethodEnvironment
CONTROL CHARTS AND CONTROL CHARTS AND GRAPHSGRAPHS
CONTROL CHARTSCHECKING WHETHER OR NOT A PROCESS IS IN CONTROL.
FACILITATING PROACTIVE ACTIONS FOR QUALITY
IMPROVEMENT.
GRAPHSMAKING DATA VISUAL
EASY FOR UNDERSTANDING AT THE WORK PLACE.
GraphsGraphs
Line GraphBar graph
Defect %
Production
Mon Tue Wed Thu
GraphsGraphs
Pie ChartScratch
Size error
hardness
Blowholes
Control ChartControl Chart
Control chart
CL
LCL
UCL