1. Quality Tools, RCA, FMEA Manufacturing Systems Analysis Professor: Nour El Kadri site.uottawa.ca

2. Source: Based on John R. Hauser. and Don Clausing, “The House of
Source: Based on John R. Hauser and Don Clausing, “The House of Quality,” Harvard Business Review, May-June 1988. x
Correlation:
Strong positive x
Positive x x
Negative x x *
Strong negative
Competitive evaluation
Engineering characteristics
Acoustic trans., window
Energy needed to close door
Check force on level ground
Energy needed to open door
Water resistance x
Door seal resistance
= Us
Importance to customer A
= Comp. A B
= Comp. B
Customer requirements
(5 is best)
Easy to close 7 x AB
Stays open on a hill 5 x AB
Easy to open 3 x AB
Doesn’t leak in rain 3 A x B
No road noise 2 x A B
Importance weighting 10 6 6 9 2 3
Relationships:
Strong = 9
Medium = 3
Target values
Reduce energy level to 7.5 ft/lb
Reduce energy to 7.5 ft/lb
Maintain current level
Reduce force to 9 lb.
Maintain current level
Maintain current level
Small = 1 5 B BA BA 4 B B x x
Technical evaluation (5 is best) A A x B 3 A x 2 x x A 1

3. Quality Tools The Seven Tools Histograms Pareto Charts
Cause and Effect Diagrams
Run Charts
Scatter Diagrams
Flow Charts
Control Charts

4. Ishikawa Democratizing Statistics
Kaoru Ishikawa developed seven basic visual tools of quality so that the average person could analyze and interpret data.
These tools have been used worldwide by companies, managers of all levels and employees.

5. Histograms A histogram is a bar graph that shows frequency data.
Histograms provide the easiest way to evaluate the distribution of data.
Histograms suggest the nature of and possible improvements for physical mechanisms at work in progress.

6. Histograms Creating a Histogram
Collect data and sort it into categories.
Then label the data as the independent set or the dependent set.
The characteristic you grouped the data by, would be the independent variable.
The frequency of that set would be the dependent variable.
Each mark on either axis should be in equal increments.
For each category, find the related frequency and make the horizontal marks to show that frequency.

7. Histograms 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.

8. Pareto Charts Pareto Chart:
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.
Remember the 80/20 rule states that approximately 80% of the problems are created by approximately 20% of the causes.
This is the economic concept that Juran applied to quality problems. The meaning behind that 80/20 rule is that there are vital few causes that create the problems.

9. Pareto Charts Constructing a Pareto Chart
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.
The steps used in Pareto analysis include: gathering categorical data, drawing the histogram, and concentrating on the high bars.

10. Pareto Charts An Example of How a Pareto Chart Can Be Used
Pareto Charts are used when products are suffering from different defects but the defects are occurring at a different frequency, or only a few account for most of the defects present, or different defects incur different costs. What we see from that is a product line may experience a range of defects. The manufacturer could concentrate on reducing the defects which make up a bigger percentage of all the defects or focus on eliminating the defect that causes monetary loss.
Data should be analyzed in two cases. The manufacturer could concentrate on reducing the defects that make up a bigger percentage of all the defects or they could concentrate on the defect that is costing them the most money. As part of the analysis, look at the tallest bars when trying to solve the problem.

11. Pareto Charts www.yourmba.co.uk/pareto_diagram.htm
Concentrating on reducing defects A, B and C since they make up 75% of all defects. Or focus on eliminating defect E, if defect E causes 40% of monetary loss.

12. Cause and Effect Diagrams
The cause and effect diagram is also called the Ishikawa diagram or the fishbone diagram.
It is a tool for discovering all the possible causes for a particular effect.
The major purpose of this diagram is to act as a first step in problem solving by creating a list of possible causes.
This tool helps workers spend time on concentrating on the causes of problems rather than focusing on improving the indications of problems.

13. Cause and Effect Diagrams
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.

14. Scatter Diagrams Scatter Diagrams
Scatter Diagrams are used to study and identify the possible relationship between the changes observed in two different sets of variables.
These relationships are can be used to recognize indicator variables in organizations.

15. Scatter Diagrams Constructing a Scatter Diagram
First, collect two pieces 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.

16. Scatter Diagrams An Example of When a Scatter Diagram Can Be Used
A scatter diagram can be used to identify the relationship between the production speed of an operation and the number of defective parts made.
A scatter diagram is used for confirming instincts about a cause-and-effect relationship between types of variables.

17. Scatter Diagrams
An Example of When a Scatter Diagram Can Be Used (cont.)
Displaying the direction of the relationship will determine whether increasing the assembly line speed will increase or decrease the number of defective parts made. Also, the strength of the relationship between the assembly line speed and the number of defective parts produced is determined.
Scatter diagrams are also used to display the direction of the relationship and displaying the strength of the relationship.

18. Flow Charts Flow Charts:
A flow chart is a pictorial representation showing all of the steps of a process.
Flow charts define and analyze processes. They build a step-by-step picture of the process for analysis, discussion, or communication purposes.

19. Flow Charts Creating a Flow Chart
First, familiarize the participants with the flow chart symbols.
Draw the process flow chart and fill it out in detail about each element.
Analyze the flow chart. Determine which steps add value and which don’t in the process of simplifying the work.
Some examples of simple symbols are: the shape of a diamond symbolizes decisions, a parallelogram represents input or output, the rectangle is the processing symbol, an arrow for flow line and so forth.

20. Flow Charts Examples of When to Use a Flow Chart
Two separate stages of a process flow chart should be considered:
The making of the product
The finished product
Flow charts are used to define, standardize, or find areas for improvement in a process

21. Run Charts Run Charts Defined
Run charts are used to analyze processes according to time or order.
Run charts are useful in discovering patterns that occur over time.

22. Run Charts Creating a Run Chart Gathering Data Organizing Data
Some type of process or operation must be available to take measurements for analysis.
Organizing Data
Data must be divided into two sets of values X and Y. X values represent time and values of Y represent the measurements taken from the manufacturing process or operation.
Charting Data
Plot the Y values versus the X values.
Interpreting Data
Interpret the data and draw any conclusions that will be beneficial to the process or operation.
When measuring data, the measurements must be taken over time and in sequential order.
When plotting the values, use an appropriate scale that will make the points on the graph visible.

23. Run Charts An Example of Using a Run Chart
An organization’s desire is to have their product arrive to their customers on time, but they have noticed that it doesn’t take the same amount of time each day of the week. They decided to monitor the amount of time it takes to deliver their product over the next few weeks.
By using a run chart, the organization can determine which day or days it is taking longer to deliver and can allow themselves more time for on-time delivery.

24. Control Charts Control Charts
Control charts are used to determine whether a process will produce a product or service with consistent measurable properties.
The process for developing a process chart is the same for almost all charts. The statistical computations is what makes it different and sometimes more complicated.

25. Control Charts Steps Used in Developing Process Control Charts
Identify critical operations in the process where inspection might be needed.
Identify critical product characteristics.
Determine whether the critical product characteristic is a variable or an attribute.
Select the appropriate process control chart.
Establish the control limits and use the chart to monitor and improve.
Update the limits.
A variable is a continuous measurement. An attribute is the result of a binomial process that results in an either-or situation.

26. Control Charts An Example of When to Use a Control Chart
Counting the number of defective products or services
Do you count the number of defects in a given product or service?
Is the number of units checked or tested constant?
Control charts focus more on acceptable limits of the process.

27. Root Cause Analysis (RCA)
If the severity of a discrepancy, or its repetitive nature demands an in-depth analysis of the root cause of the problem, the we should complete a Root Cause Analysis & Problem Solving.
RCA combines several effective tools for identifying and resolving problems
It forces the user to document the entire process from identifying potential causes, conducting a 5-Why analysis, determining countermeasures, and establishing an action plan for preventative action

28. Root Cause Analysis What is Root Cause Analysis?
- Finding the real cause of the problem and dealing with it rather than simply continuing to deal with the symptoms
Reactive method
Goals
- Failure identification
- Failure analysis
- Failure resolution
Iterative Process:
- Complete prevention of recurrence by a single intervention is not always possible.

29. Steps for Root Cause Analysis
Collection of data - Phase I
- A fact-finding investigation, and not a fault-finding mission
Event Investigation - Phase II
- Objective evaluation of the data collected to identify any causal factor that may have led to the failure
Resolution of occurrence - Phase III
- Realistic assessment of the viability of the corrective action that the previous phase revealed.
- The phenomenon must then be monitored periodically to verify resolution.

30. Why do we need it Benefits of RCA
- Real cause of the problem can be found
- Problem recurrence will be minimized

31. Types of RCA Safety-based RCA Production-based RCA Process-based RCA
Systems-based RCA

32. Types of RCA Safety-based RCA
- Investigating Accident and occupational safety and health.
- Root causes: unidentified risks, or inadequate safety engineering, missing safety barriers.
Production-based RCA
- Quality control for industrial manufacturing.
- Root causes: non-conformance like, malfunctioning steps in production line.

33. Types of RCA Process-based RCA - Extension of Production-based RCA.
- Includes business processes also.
- Root causes: Individual process failures
System-based RCA
- Hybrid of the previous types
- New concepts includes: change management, systems thinking, and risk management.
- Root causes: organizational culture and strategic management 33

34. Methods of Root Cause Analysis
Change Analysis
Barrier Analysis
MORT: Management Oversight and Risk Tree
Human Performance Evaluation (HPE) 34

35. Kepner-Tregoe Method Developed in 1958
Fact-based approach to systematically rule out possible causes and identify the true cause.
Composed of fives Steps:
- Define the Problem
- Describe the Problem
- Establish possible causes
- Test the most probable cause
- Verify the true cause
Kepner-Tregoe is a mature process with decades of proven capabilities.
Kepner-Tregoe Problem Analysis was used by NASA to troubleshoot Apollo XIII. 35

36. Tools for Root Cause Analysis
Add diagrams Diagrams 36

37. Failure Mode Effect and Analysis (FMEA)
Methodology for analyzing potential reliability problems early in the development cycle.
Failure modes are any errors or defects in a process, design, or item, especially customer related.
Effects analysis refers to studying the consequences of those failures. 37

38. FMEA Example
Source: 38

39. FMEA
Benefits:
Improves the quality, reliability, and safety of products.
Increases customer satisfaction.
Stimulates open communication and collective expertise.
Disadvantages:
Assumes cause of problem is a single event.
Examination of human error overlooked. 39

40. Fishbone Analysis cause cause reason cause cause reason Components :
- Head of a Fish : Problem or Effect
- Horizontal Branches : Causes
- Sub-branches : Reason
- Non-service Categories : Machine, Manpower, Method etc.
- Service categories : People, Process, Policies, Procedures etc.
Machine
Material
Measurement
cause
cause
reason
Problem
cause
cause
reason
Management
Method
Man Power 40

41. Fishbone Diagrams An Example of When a Fishbone diagram can be used
This diagram can be used to detect the problem of incorrect deliveries.
Diagram on next slide
When a production team is about to launch a new product, the factors that will affect the final product must be recognized. The fishbone diagram can depict problems before they have a chance to begin.
Advantages
- Helps to discover the most likely ROOT CAUSES of a problem
- Teach a team to reach a common understanding of a problem.
The effect being examined is normally an aspect of product or service quality.

42. Fishbone (Cause and Effect) Diagrams
Diagram of the Incorrect Deliveries Example:
You continue the process of branching off into more and more directions until every possible cause has been identified. The final result will represent a pile of all the factors relating to the effect being explored and the relationships between them.
Source:

43. Fishbone Analysis 5 WHY’S WHY WHY WHY WHY WHY Car stopped
Middle of the road
Ran out of Gas
Didn’t buy
this morning
WHY
WHY
WHY
Didn’t have
money
Lost them in
last night’s poker
WHY
WHY
Not very good
in “bluffing” 43

44. RCA-Goodrich Aerostructures
The first step is to clearly define the problem

45. Root Cause Analysis (RCA)
Assemble a multi-disciplined team of people who are involved in the process
List the actions taken to prevent the problem from reaching the customer

46. Root Cause Analysis (RCA)
Schedule a brainstorming session and use the fishbone diagram to document all possible (not just probable) causes for the problem

47. Root Cause Analysis (RCA)
From the fishbone diagram, choose the top 3 probable causes
Use the 5-Whys and drill down to determine root cause for each of the 3 probable causes

48. Root Cause Analysis (RCA)
For each of the 3 most probable root causes, establish countermeasures and a plan of action to address each area

49. Root Cause Analysis (RCA)
Finally, verify that all the actions are complete, that similar products have been reviewed as well, and that the team concurs that the countermeasures have been effective

50. References http://www.isixsigma.com/library/content/c020610a.asp