Description
The tools explained are flowcharts, check sheet, histograms, cause and effect diagram, pareto diagrams, scatter diagram and control charts.
Quality Tools
Quality Tools
• Quality Tools are “tools that help organizations understand their processes to improve them.”
• These methods are utilized by quality professionals to aid in the analysis,documentation, and organization of quality systems. • Each tool helps in visualizing sources of variation. • Used primarily for problem solving. • They are designed so that workers at all levels can understand the process and procedure of a system.
The Quality Tools…..
Flow charts : Check sheet : Histograms : Understand the mess; Establish procedures. Finding facts. Identifying problems.
Cause and Effect Diagram : Generating ideas, Identify problems. Pareto diagrams : Understand the mess; Identify problems.
Scatter Diagram : Developing solutions. Control charts : Understanding the mess; holding the gains.
Flow Charts…
• Flowcharts are a visual diagram of a process broken down by activities. • Document processes as they flow from start to finish and they show how each step is related. • At a high level, help users understand complex processes without confusing details.
• At a detail level, they help users analyze their processes for optimization and improvements.
Flow Charts…Construction
Select a start and stop point (define boundaries).
List major steps/tasks and decision points (list, in order, the steps or tasks and possible decisions). Use standardized graphical symbols to document the process, e.g. = start/stop = dir. of flow
= step/task
= decision
Review the results (compare to real process and verify it is complete and accurate).
Flow Charts…Example
Working of Pizza Villa
Open the Restaurant Take Customer Order
Go to chef
Wait till available/ take new orders
no
Pizza Available?
yes Take it to the customer
Flow Charts…Example
Wait till customer has his food
Ask if more is needed
Go to chef Yes
No
Get the bill and pay
Yes
Time to close?
Stop
Close the Restaurant
No
Take customer order
Check List
• Check sheets are forms used to summarize a tally count of event occurrences.
• Count the number of occurrences, such as defects, for an event (e.g. inspection, audit etc).
• Design the check sheet for a given application (include relevant information for later reference).
• Record the data in space provided (place an “X” or other mark for each occurrence). • For primary data collection for other quality tools such as Pareto charts and histograms.
Check Sheet
Days
???
Defect Type
???? ??? ???? ??
?
???
??
??? ?
Check Sheet
COMPONENTS REPLACED BY LAB TIME PERIOD: 22 Aug to 27 Aug 2005 REPAIR TECHNICIAN: Sunil TV SET MODEL 1013
Integrated Circuits Capacitors Resistors Transformers CRT
|||| |||| |||| |||| |||| |||| || || |||| |
Histogram
A histogram is a bar graph that shows frequency data. Histograms provide the easiest way to evaluate the distribution of data.
How to construct a Histogram: Collect data and sort it into categories.
Label the data into sets (independent/ dependent).
The characteristic you grouped the data would be independent variable. The frequency of that set would be the dependent variable.
For each category, Find the related frequency and make the horizontal marks to show that frequency.
Examples of How Histograms Can Be Used Histograms can be used to determine distribution of sales. Say for instance a company wanted to measure the revenues of other companies and wanted to compare numbers. <<<<<< << See Excel sheet (histogram.xls) for Example >>>>>>>>
Cause and Effect Diagram
Also known as … Fishbone diagrams Ishikawa diagrams
Show the relationships between a problem and its possible causes
Constructing a Cause and Effect Diagram
First, clearly identify and define the problem or effect for which the causes must be identified. Place the problem or effect at the right or the head of the diagram. Identify all the broad areas of the problem.
Write in all the detailed possible causes in each of the broad areas.
Each cause identified should be looked upon for further more specific causes.
View the diagram and evaluate the main causes.
Set goals and take action on the main causes.
Cause and Effect Diagram an Example…
Measurement
Faulty testing equipment Incorrect specifications Improper methods
Human
Machines
Out of adjustment Tooling problems Old / worn
Poor supervision Lack of concentration Inadequate training
Inaccurate temperature control Dust and Dirt
Quality Problem
Defective from vendor Not to specifications Materialhandling problems Poor process design Ineffective quality management Deficiencies in product design
Environment
Materials
Process
Cause and Effect Diagram an Example…
Pareto Diagram
Pareto charts are used to identify and prioritize problems to be solved. They are actually histograms aided by the 80/20 rule adapted by Joseph Juran.
The 80/20 rule states that approximately 80% of the problems are created by approximately 20% of the causes.
Constructing Pareto Diagram
First, information must be selected based on types or classifications of defects that occur as a result of a process.
The data must be collected and classified into categories. Then a histogram or frequency chart is constructed showing the number of occurrences.
Pareto Diagram Example:
100 90 80 70 60 50 40 30 20 10 0 1 2 3 4 5 6 7
The chart shows the number of defects rectified in a casting
1. 2. 3. 4. 5. 6. 7.
Poor design Wrong dimensions Defective parts Machine calibration Operator Error Defective material Surface abrasion
Pareto Diagram for progressive analysis:
1400
Which assembly has maximum defects ?
Assembly 5
1200 1000 800 600 400 200 0 Assembly 5 Assembly 2 Assembly 3 Assembly 1
90 80 70 60
What are the common defects? Electrical
50 40 30 20 10 0 Electrical Assembly Soldering Finishing
40
What electrical components contribute most of the defects ? Relays
35 30 25 20 15 10 5 0 Relay Capacitor Transistor Resistor Switch PCB
30
What is the most common way in which the relay fails? Thermal
25 20 15 10 5 0 Thermal Offset Noise Dust Flux
Scatter Diagram
• Supplies the data to confirm a hypothesis that two variables are related.
• Provides both a visual and statistical means to test the strength of a relationship. • Provides a good follow-up to cause and effect diagrams.
Constructing a Scatter Diagram ? First, collect two types of data and create a summary table of the data. ? Draw a diagram labeling the horizontal and vertical axes.
It is common that the “cause” variable be labeled on the X axis and the “effect” variable be labeled on the Y axis.
? Plot the data pairs on the diagram. ? Interpret the scatter diagram for direction and strength.
Scatter diagram Patterns
Example
Control Charts
Used to determine whether a process will produce a product or service with consistent measurable properties
Identify critical operations in the process where inspection might be needed.
Establish the control limits and use the chart to monitor and improve. Update the limits. Determine whether the critical product characteristic is a variable or an attribute.
Data types:
Variable or Attribute Data
Variable is measured on a continuous scale Attribute is occurrences in n observations
Deviation from Mean Upper and Lower Spec’s Range
doc_200154778.pptx
The tools explained are flowcharts, check sheet, histograms, cause and effect diagram, pareto diagrams, scatter diagram and control charts.
Quality Tools
Quality Tools
• Quality Tools are “tools that help organizations understand their processes to improve them.”
• These methods are utilized by quality professionals to aid in the analysis,documentation, and organization of quality systems. • Each tool helps in visualizing sources of variation. • Used primarily for problem solving. • They are designed so that workers at all levels can understand the process and procedure of a system.
The Quality Tools…..
Flow charts : Check sheet : Histograms : Understand the mess; Establish procedures. Finding facts. Identifying problems.
Cause and Effect Diagram : Generating ideas, Identify problems. Pareto diagrams : Understand the mess; Identify problems.
Scatter Diagram : Developing solutions. Control charts : Understanding the mess; holding the gains.
Flow Charts…
• Flowcharts are a visual diagram of a process broken down by activities. • Document processes as they flow from start to finish and they show how each step is related. • At a high level, help users understand complex processes without confusing details.
• At a detail level, they help users analyze their processes for optimization and improvements.
Flow Charts…Construction
Select a start and stop point (define boundaries).
List major steps/tasks and decision points (list, in order, the steps or tasks and possible decisions). Use standardized graphical symbols to document the process, e.g. = start/stop = dir. of flow
= step/task
= decision
Review the results (compare to real process and verify it is complete and accurate).
Flow Charts…Example
Working of Pizza Villa
Open the Restaurant Take Customer Order
Go to chef
Wait till available/ take new orders
no
Pizza Available?
yes Take it to the customer
Flow Charts…Example
Wait till customer has his food
Ask if more is needed
Go to chef Yes
No
Get the bill and pay
Yes
Time to close?
Stop
Close the Restaurant
No
Take customer order
Check List
• Check sheets are forms used to summarize a tally count of event occurrences.
• Count the number of occurrences, such as defects, for an event (e.g. inspection, audit etc).
• Design the check sheet for a given application (include relevant information for later reference).
• Record the data in space provided (place an “X” or other mark for each occurrence). • For primary data collection for other quality tools such as Pareto charts and histograms.
Check Sheet
Days
???
Defect Type
???? ??? ???? ??
?
???
??
??? ?
Check Sheet
COMPONENTS REPLACED BY LAB TIME PERIOD: 22 Aug to 27 Aug 2005 REPAIR TECHNICIAN: Sunil TV SET MODEL 1013
Integrated Circuits Capacitors Resistors Transformers CRT
|||| |||| |||| |||| |||| |||| || || |||| |
Histogram
A histogram is a bar graph that shows frequency data. Histograms provide the easiest way to evaluate the distribution of data.
How to construct a Histogram: Collect data and sort it into categories.
Label the data into sets (independent/ dependent).
The characteristic you grouped the data would be independent variable. The frequency of that set would be the dependent variable.
For each category, Find the related frequency and make the horizontal marks to show that frequency.
Examples of How Histograms Can Be Used Histograms can be used to determine distribution of sales. Say for instance a company wanted to measure the revenues of other companies and wanted to compare numbers. <<<<<< << See Excel sheet (histogram.xls) for Example >>>>>>>>
Cause and Effect Diagram
Also known as … Fishbone diagrams Ishikawa diagrams
Show the relationships between a problem and its possible causes
Constructing a Cause and Effect Diagram
First, clearly identify and define the problem or effect for which the causes must be identified. Place the problem or effect at the right or the head of the diagram. Identify all the broad areas of the problem.
Write in all the detailed possible causes in each of the broad areas.
Each cause identified should be looked upon for further more specific causes.
View the diagram and evaluate the main causes.
Set goals and take action on the main causes.
Cause and Effect Diagram an Example…
Measurement
Faulty testing equipment Incorrect specifications Improper methods
Human
Machines
Out of adjustment Tooling problems Old / worn
Poor supervision Lack of concentration Inadequate training
Inaccurate temperature control Dust and Dirt
Quality Problem
Defective from vendor Not to specifications Materialhandling problems Poor process design Ineffective quality management Deficiencies in product design
Environment
Materials
Process
Cause and Effect Diagram an Example…
Pareto Diagram
Pareto charts are used to identify and prioritize problems to be solved. They are actually histograms aided by the 80/20 rule adapted by Joseph Juran.
The 80/20 rule states that approximately 80% of the problems are created by approximately 20% of the causes.
Constructing Pareto Diagram
First, information must be selected based on types or classifications of defects that occur as a result of a process.
The data must be collected and classified into categories. Then a histogram or frequency chart is constructed showing the number of occurrences.
Pareto Diagram Example:
100 90 80 70 60 50 40 30 20 10 0 1 2 3 4 5 6 7
The chart shows the number of defects rectified in a casting
1. 2. 3. 4. 5. 6. 7.
Poor design Wrong dimensions Defective parts Machine calibration Operator Error Defective material Surface abrasion
Pareto Diagram for progressive analysis:
1400
Which assembly has maximum defects ?
Assembly 5
1200 1000 800 600 400 200 0 Assembly 5 Assembly 2 Assembly 3 Assembly 1
90 80 70 60
What are the common defects? Electrical
50 40 30 20 10 0 Electrical Assembly Soldering Finishing
40
What electrical components contribute most of the defects ? Relays
35 30 25 20 15 10 5 0 Relay Capacitor Transistor Resistor Switch PCB
30
What is the most common way in which the relay fails? Thermal
25 20 15 10 5 0 Thermal Offset Noise Dust Flux
Scatter Diagram
• Supplies the data to confirm a hypothesis that two variables are related.
• Provides both a visual and statistical means to test the strength of a relationship. • Provides a good follow-up to cause and effect diagrams.
Constructing a Scatter Diagram ? First, collect two types of data and create a summary table of the data. ? Draw a diagram labeling the horizontal and vertical axes.
It is common that the “cause” variable be labeled on the X axis and the “effect” variable be labeled on the Y axis.
? Plot the data pairs on the diagram. ? Interpret the scatter diagram for direction and strength.
Scatter diagram Patterns
Example
Control Charts
Used to determine whether a process will produce a product or service with consistent measurable properties
Identify critical operations in the process where inspection might be needed.
Establish the control limits and use the chart to monitor and improve. Update the limits. Determine whether the critical product characteristic is a variable or an attribute.
Data types:
Variable or Attribute Data
Variable is measured on a continuous scale Attribute is occurrences in n observations
Deviation from Mean Upper and Lower Spec’s Range
doc_200154778.pptx