1. Chapter 7 Quality Tools

2. Which tool is best?
Tools can serve as the backbone for virtually any type of quality improvement effort (Six Sigma, TQM, 8D)
Graphical representations of data help us understand the true importance of data.
There is no single one-size fits all solution. Every project and problem is different.

3. Diagnostic Tools Graphical Tools: Analytical Tools: Histogram
Boxplots
Probability distribution plots
Main-effects plots
Pareto charts
Run charts
Multi-Vari charts
Time-series plots
Scatter plots
Analytical Tools:
Cause-Effect (CE) diagram
Failure mode-effects Analysis (FMEA)
XY matrix
Affinity diagram
Fault tree analysis (FTA)

4. Diagnostic Tools Graphical Rep. of Process: Other Tools: Checksheets
Process flow charts
Process mapping
Cross-functional mapping
Deployment diagram
Supplier-input-process-output-customer (SIPOC) diagram
Input-process-output (IPO) diagram
Force-field analysis
Other Tools:
Checksheets
Scorecards

5. Problem Definition
A good problem definition will include quantified information about the problem, the magnitude of the problem, the baseline, and the gap remaining to reach a benchmark or desired state
Be Specific
Use declarative format
Quantify
Be factual
Example of poor problem definition: “Reduce restorable time for severity 1 telephone banking problems, focusing on human errors as root cause”
Example of good problem definition: “Reduce restorable time from 51% per month for severity 1 telephone banking problems to 30% or less per month by the third quarter of this year, resulting in annual savings of $4.5M”

6. Uncontrollable variables or factors (noise)
Y = f (x)
The transfer equation of Y=f(x) where X =x1, x2, x3,…,xn recognizes that a causal relationship exits in any process of action performed.
Y is a function of one or many x’s where Y is the dependent variable and the x’s are independent variables.
X can equal quality, delivery time, cost of the product. Therefore Critical to Satisfaction refers to any variable that has significant influence on one of more of the determinants of customer satisfaction.
Pareto principal suggests that 80% of the of the total error or variance will be caused by 20% of the variables. These are the “vital few”, while the remaining are the “trivial many”. The key is to identify these vital few.
x1 x2 x xn
Uncontrollable variables or factors (noise)
Inputs
Process
. . .

7. Critical-to (CT) Definitions
Critical-to-Satisfaction (CTS) characteristics – expression of the customer’s vital needs.
Critical-to-Quality (CTQ) characteristics- the product, service and/or transactional characteristics that significantly influence one or more CTS in terms of quality.
Critical-to-Delivery (CTD) characteristics- “ “ “ “ in terms of delivery.
Critical-to-Cost (CTC) characteristics “ “ “ “ in terms of cost.
Critical-to-Process (CTP) characteristics- Process parameters that significantly influence a CTQ, CTD, and/or CTC.
Critical to Satisfaction
Delivery
CTD
Quality
CTQ
CTP
Price
CTC
Variables (X)

8. The Leverage Principle
Not all X variable affect the outcome (Y) equally.
In Six Sigma process:
Identify the variables that exert strong influence (Vital Few).
Then we must focus on controlling these variables. Design of Experiments (DOE) is used to achieve this objective. Y
X (x1, x2, x3,…,xn )
Dependent
Independent
Output
Input-process
Effect
Cause
Symptom
Problem
Monitor
Control

9. The Leverage Principle (Variation Reduction Strategies)
Strategy 1 2 3 4 5 6
Total Red. Efforts
Total
% Impr.
Baseline 4 11 3 2 1 --
12.33
Reduce each by 1 10 6
10.68
13.4%
Eliminate all but one
11.00
10.8%
Reduce the vital one 8
9.75
20.9%

10. What does measurement mean?
Concept of measurement: seek to compare or contrast a physical attribute of something to a rational and invariant standard  performance gap
Seek to quantify such gaps for purposes of communications, verification, and analysis.
Measure subjective matter (customer satisfaction) through surveys, questionnaires
Measure physical characteristics, time characteristics, defect rates….

11. How do we know if customers are happy
How do we know if customers are happy? Goal is to understand how to better satisfy the customer
Survey design considerations:
Length (not too long)
Appearance (simple, not busy)
Types of questions (statements of fact or measures of performance or importance)
Types of question formats:
Closed-ended (yes/no)
Rating scales
Open-ended questions / probes
Other considerations:
Focus on one theme
Usually best to include a midpoint in rating scales (i.e. odd number)
Try to solicit feelings toward your competitors.
Identify specific target control groups:
At least 10% of customer base
Stratify various customer segments
Give prior notice, before delivering survey
Personalize the survey and cover letter
Address confidentiality
Offer an incentive or token of appreciation for completion
Follow up with a friendly collection strategy
Develop action plans that are based on results
Communicate results to customers
Follow up with repeat surveys to monitor changes over time

12. Likert scale
A subjective scoring system that allows a person being surveyed to quantify likes and preferences on a 5-point scale, with 1 being the least important, relevant, interesting, or other, and 5 being most excellent, important, etc
Strongly Agree / Agree / Undecided / Disagree / Strongly Disagree
Very Frequently /Frequently /Occasionally /Rarely /Very Rarely /Never
Very Important / Important / Moderately Important / Of Little Importance / Unimportant
Excellent / Above Average / Average / Below Average /Extremely Poor
Almost Always True / Usually True / Often True / Occasionally True / Sometimes But Infrequently True / Usually Not True / Almost Never True

13. Continuous Scales
Linear Scale: A scale with equal divisions for equal values
If the data are nonlinear (i.e., with a very wide range of values), then a logarithmic scale (in this case base 10) may be more appropriate.

14. Analytical Tool: Cause-Effect (CE) Analysis
CE diagram (fishbone diagram) uses collective knowledge to identify the main causes (x) of the effect (y) under study.
Manufacturing diagrams (Six M’s: measurement, manpower, machines, materials, methods, and mother nature).
Transactional diagrams (4 P’s :Policies, procedures, personnel, environment).
Graphical way to show relationships between inputs and outputs.
Label each cause with a “C” (fixed variable), “N” (Noise) or “X” (experimental independent variable.)
CE Diagrams can be constructed using MINITAB (page )

15. Cause-Effect (CE) Analysis

16. Analytical Tool: Failure Mode – Effects Analysis (FMEA)
Used to assess risks from potential product , service, transaction or process failure modes.
Widely used in the Analyze and Improve phase, can also be used in Control phase.
Helpful to assist in:
Improving or designing more robust products, services & processes
Designing safer products and processes
Designing safer delivery systems
Receiving fewer complaints and reducing the organization’s guarantee costs
Creating fewer problems or minimizing them in everyday business processes
Provide improvement teams with prioritized causes and identifying which causes need to be eliminated urgently.

17. How does FMEA work?
Focus on Severity, Occurrence and Detectability of each process. Then calculate the the Risk Priority number (RPN)
Each organization can define their own scale (1-10, 1-5… )as long as they are consistent across the organization.
Example of FMEA analysis for Auto manufacturer
Start with a grid to define the potential failures
Product or Process
Failure Mode
Failure Effects
SEV
Causes
OCC
Controls
DET
RPN
Actions
Plans PS PO PD
PRPN
Engine
Overheat
Engine Damage
Battery
Doesn't retain charge
Car doesn't start
Brakes
Brake failure
Can't STOP car

18. FMEA Severity, Occurrence & Detectability
Rating
Criteria 1
Is not noticed by anybody, has no effect 2
Is not noticed, has only an insignificant effect 3
Causes only small irritations 4
Modest loss of performance 5
Fall in performance level; consequence is customer's complaints 6
Fall in performance level that disturbs the capacity to function 7
Disturbed capacity function that leads to an increase in customer dissatisfaction 8
Product or service becomes useless 9
Product or service is illegal 10
Customer or employee is injured or killed.
SEVERITY
Product or Process
Failure Mode
Failure Effects
SEV
Causes
OCC
Controls
DET
RPN
Actions
Plans PS PO PD
PRPN
Engine
Overheat
Engine Damage
Battery
Doesn't retain charge
Car doesn't start
Brakes
Brake failure
Can't STOP car

19. FMEA Severity, Occurrence & Detectability
Rating
Criteria
Probability 1
Once every yrs
<2/1,000,000,000 2
Once every 3-6 yrs
<3/10,000,000 3
Once every 1-3 yrs
<6/1,000,000 4
Once a year
<6/100,000 5
Once every 6 months
<1/10,000 6
Once every 3 months
<0.33% 7
Once a month
<1% 8
Once a week
<5% 9
Every 3 to 4 days
<30% 10
More than once a day
>30%
OCCURANCE

20. FMEA Severity, Occurrence & Detectability
PROBABILITY OF DETECTION
Rating
Criteria 1
The cause of the failure is obvious and can be hindered simply 2
All units are to be inspected automatically 3
Statistical process controls with a systematic failure cause test and corresponding Actions 4
Statistical process controls are to be conducted with a systematic failure cause test. 5
Statistical process controls are to be conducted 6
All units are to be inspected manually and avoidance actions installed 7
All units are to be inspected manually 8
Manual inspections are to be conducted frequently 9
Manual inspections are to be conducted occasionally. 10
The defect caused by the failure is not detectable
Risk Priority number (RPN) is calculated by multiplying
Severity x Occurrence x Detectabillity

21. Analytical Tool: XY Matrix
XY matrix allows everyone involved with a process to agree on output (y’s) critical to the survey, transaction and/or customer.
Matrix allows the team to assign the level of importance of each variable (x) to the output (y).
EXAMPLE of XY matrix as relates to a coffee house.
If the results/ranking were generated during a brainstorm session than they should be verified based on actual data.

22. Graphical Tool: Pareto Charts
Pareto charts help identify the top factors (“vital few”)
Order X in descending order.
Add a line showing cumulative % of total.
Based on this which inputs would you focus on to insure customer satisfaction?

23. Graphical Tool: Histogram with Normal Curve
university-software.com/NormalHist.jpg

24. Graphical Tool: Histogram with Normal Curve
Minitab:
Calc
Random Data
Integer
Stat
Basic Statistics
Graphical Summary

25. Graphical Tool: Boxplot
Minimum
Maximum
Median
First Quartile
Third Quartile
Minitab:
Stat
Basic Statistics
Display Descriptive..
Boxplot

26. Graphical Tool: Probability Plot
Minitab:
Graph
Probability Plot
Single

27. Graphical Tool: Main-Effects Plot
Main-effects plot graphically compares the level of a process output variable at various states of process factors
Lines with steeper slopes have larger impact on the output compared to those lines with little or no slope
Used to present result from analysis of variance (ANOVA)
Use to examine the level means for each factor, compare the level means for several factors and compare the relative strength of the effects across factors

28. Graphical Tool: Main-Effects Plot
MINITAB
STAT
ANOVA
Main Effect Plot
Input
Output X1 60 1 83 X2 72 71 X3 74 69

29. Graphical Tool: Run Chart
A line graph of data points plotted in chronological order that helps detect special causes of variation
Understand process variation
Analyze data for patterns
Monitor process performance
Communicate process performance

30. Graphical Tool: Run Chart

31. Graphical Tool: Time-Series Plot
A time series plot is a graph showing a set of observations taken at different points in time and charted in a time series.
Outliers: values that do not appear to be consistent with the rest of the data
Discontinuities: a break or gap in a process that would normally be continuous
Trends: a general tendency in movement or direction
Periodicities: any recurrence at regular intervals

32. Graphical Tool: Time-Series Plot
cookbooks.opengrads.org/images/3/3b/Precip_ti..

33. Graphical Tool: Multi-Vari Charts
Show patterns of variation from several possible causes on a single chart, or set of charts
Obtains a first look at the process stability over time. Can be constructed in various ways to get the “best view”.
Positional: variation within a part or process
Cyclical: variation between consecutive parts or process steps
Temporal: Time variability

34. Graphical Tool: Multi-Vari Charts
Cus. Size
Product
Cus. Type
Satis. 1 2
3.54 3
3.16
2.42
2.70
3.31
4.12
3.24
4.47
3.83
2.94
Cus. Size: 1 = small
2 = large
Product: 1 = Consumer
2 = Manuf.
Cus. Type: 1 = Gov’t
2 = Commercial
3 = Education

35. Graphical Tool: Multi-Vari Charts
Minitab:
Stat
Quality Tools
Multi Vari Chart

36. Graphical Tool: Scatter Plot
Show patterns of variation from several possible causes on a single chart, or set of charts
Obtains a first look at the process stability over time. Can be constructed in various ways to get the “best view”.
Positional: variation within a part or process
Cyclical: variation between consecutive parts or process steps
Temporal: Time variability

37. Graphical Tool: Scatter Plot

38. Graphical Tool: Scatter Plot

39. Graphical Tool: Scatter Plot

40. Graphical Tool: Scatter Plot

41. Graphical Tools for Process Rep.: Process Flowcharts
Visual representation of the major process steps.
Useful to compare “as is” with “should be” process.
Determine the limits of the process. Clearly define where it begins & ends.
Determine the steps in the process
Put the steps into sequence
Draw the flow using standard symbols. Add arrows to show flow direction.
Verify the flow is complete. Is every feedback loop complete?
Standard symbols:
Stop/ Start
Decision Point
Activity
Connector (to another page or diagram)

42. Graphical Tools for Process Rep.: Process Flowcharts

43. Graphical Tools for Process Rep.: Process Mapping
Process mapping is a workflow diagram to bring forth a clearer understanding of a process or series of parallel processes
Cross-Functional Mapping
“As-is” vs. “To-be”

44. Graphical Tools for Process Rep.: Process Mapping

45. Graphical Tools for Process Rep.: SIPOC Diagram
Supplier-Input-Process-Output-Customer diagram.
A high-level picture of the process that depicts how the given process is servicing the customer.
Useful to discover customer “pain points”
Identify key Y’s an X’s with project team.
Suppliers
Inputs
Process
Outputs
Customers
Machine manufacturer
Bean supplier
Filter supplier
Cup supplier
Coffee beans
Water
Filter
Cup
Brewing machine
Insert simple flow-chart here
Coffee
Espresso
Repeat (daily)
New

46. Graphical Tools for Process Rep.: SIPOC Diagram

47. Graphical Tools for Process Rep.: IPO Diagram
Input-Process-Output diagram is another visual rep. of a process activity. Based on the transfer equation y=f(x)
Fixed Variables (C)
Supply Chain
SOPs
Process X’s
x1=Forecast
x2=Buyer
X3 =AVL
x4=BOM
x5=LT
x6=Market Dollar Value
Process
Program Management
Y=Lack of materials supplies
Unforecast demand
Environment
AVL
Accuracy
Shipping from
Supplier
Noise Variables(N)

48. Graphical Tools for Process Rep.: SIPOC Diagram

49. Other Tools: Force-Field Analysis
Force-Field Analysis was developed by Lewin (1951) and is widely used to inform decision-making, particularly in planning and implementing change management programs in organizations.
It is a powerful method for gaining a comprehensive overview of the different forces acting on a potential policy issue, and for assessing their source and strength.

50. Force -Field Analysis

51. Other Tools: Matrix Analysis
Technique for finding new combinations of products or services.
List the attributes of the product, service or strategy
Draw up a table using these attributes as column headings
Write down as many variations of the attribute as possible within these columns.
Select one entry from each column. By mixing one item from each column, you will create a new mixture of components. This is a new product, service or strategy.
Finally, evaluate and improve that mixture to see if you can imagine a profitable market for it.

52. Other Tools: Matrix Analysis

53. Other Tools: Checksheets
A check sheet is a structured, prepared form for collecting and analyzing data
Decide what event or problem will be observed. Develop operational definitions.
Decide when data will be collected and for how long.
Design the form. Set it up so that data can be recorded simply by making check marks or Xs or similar symbols and so that data do not have to be recopied for analysis.
Label all spaces on the form.
Test the check sheet for a short trial period to be sure it collects the appropriate data and is easy to use.
Each time the targeted event or problem occurs, record data on the check sheet.

54. Other Tools: Checksheets

55. Other Tools: Scorecards
A balanced scorecard is a central list of numbers, which show each key part of an organization's success, such as financials, people, operations, suppliers, customers, and support systems.
The numbers should measure not just important outcomes, but also the factors which influence, or drive, those outcomes.

56. Other Tools: Scorecards

57. Other Tools: Affinity Diagram
The affinity diagram organizes a large number of ideas into their natural relationships
Record each idea with a marking pen on a separate sticky note or card. Randomly spread notes on a large work surface so all notes are visible to everyone.
Look for ideas that seem to be related in some way. Place them side by side. Repeat until all notes are grouped.
Participants can discuss the shape of the chart, any surprising patterns, and especially reasons for moving controversial notes. When ideas are grouped, select a heading for each group.
Combine groups into “supergroups” if appropriate.

58. Other Tools: Affinity Diagram

59. Affinity Diagram