sqc guest lecture- starbucks
DESCRIPTION
Guest lecture for Rutgers Graduate Statistical Quality Control 8/7/2012TRANSCRIPT
SQC Guest Lecture
Introduction
Goals for Today
Show you to see and (perhaps) solve problems differently
About Me• Academics
– MS Industrial Engineering Rutgers University – BS Electrical & Computer Engineering Rutgers University – BA Physics Rutgers University
• Professional– Principal Industrial Engineer -Medrtonic– Master Black belt- American Standard Brands– Systems Engineer- Johnson Scale Co
• Awards– ASQ Top 40 Leader in Quality Under 40
• Certifications– ASQ Certified Manager of Quality/ Org Excellence Cert # 13788 – ASQ Certified Quality Auditor Cert # 41232 – ASQ Certified Quality Engineer Cert # 56176 – ASQ Certified Reliability Engineer Cert #7203 – ASQ Certified Six Sigma Green Belt Cert # 3962– ASQ Certified Six Sigma Black Belt Cert # 9641– ASQ Certified Software Quality Engineer Cert # 4941
• Publications– Going with the Flow- The importance of collecting data without holding up your processes- Quality Progress March
2011– "Numbers Are Not Enough: Improved Manufacturing Comes From Using Quality Data the Right Way" (cover story).
Industrial Engineering Magazine- Journal of the Institute of Industrial Engineers September (2011): 28-33. Print
Agenda
Todays slides are available on Sakai
Also Please Complete the Online Feedback Surveyhttps://www.surveymonkey.com/s/39N9Y9X
18:00 18:20 Introduction
18:20 18:40 Measure
18:40 19:00 Define
19:00 19:20 Brainstorm
19:20 19:40 Break
19:40 20:00 Depict the Data
20:00 20:20 Make Control Charts
20:20 20:40 Process Mapping
20:40 21:00 Map the process
21:00 21:20 Analyze
21:20 21:55 Conclusion
So Lets Get Moving
What is a Process?• Formal Definition
– A systematic series of actions directed to some end• Practical Definition
– Any Verb Noun Combination • Eat Sandwich• Read Book• Attend Conference
• Implications of Practical Definition– Same Tools Techniques and Methods of the Lean Six Sigma
Methodologies can be used for virtually anything
Inputs• People• Materials• Methods• Mother Nature• Management• Measurement
System
Process• Sequence of
Value Added Steps
Outputs• Products
• Hardware• Software• Systems• People
• Services
Lean Tool Kit
• 5S- – Sort– Straighten– Shine– Standardize– Sustain
• Value Stream Mapping• Kanban• Poka-yoke• Kaizen <- mean continuous improvement
Six Sigma Tool Kit
• DMAIC– Define– Measure– Analyze– Improve– Control
• SIPOC Diagrams • Statistical Process Control • 5 Whys
The analogy
The task is to undo a bolt.
Solution 1- Ratchet and Socket
Solution 2- Open Ended /Box Wrench
Solution 3- Vice Grips
Which is Correct?
The Answer
• It depends.– There are certain applications that demand a open
ended wrench– Others require a socket– Finally there are situations that require vice grips
• Most cases all three solutions will work• The same is true for solving Continuous
Improvement problems
Types of Statistics
• Descriptive Statistics– Present data in a way that will facilitate
understanding• Inferential Statistics
– Analyze sample data to infer properties of the population from which the sample is drawn
• Statistical Significance Does not Mean actual significance.– (See US Supreme Court Matrixx Initiatives, Inc. v.
Siracusano
Normal Distribution
• Also known as Gaussian, Laplace–Gaussian or standard error curve
• First proposed by de Moivre in 1783• Independently in 1809 by Gauss
All Normal Distributions Defined by two things1. The Average µ2. The Standard Deviation σ
Page 143
Area Under the Curve
(c) Probabilities and numbers of standard deviations
Shaded area = 0.683 Shaded area = 0.954 Shaded area = 0.997
68% chance of fallingbetween and
95% chance of fallingbetween and
99.7% chance of fallingbetween and
Effect of Changing Parameters
160 180 200140 160 180
shifts the curve along the axis
200 140
2 =174
2 = 61 =1 = 6
2 = 12
2 =1701 =
increases the spread and flattens the curve
(a) Changing (b) Increasing
1 = 160
15
What is Process Sigma?
A 3s process (3 standard deviations fit between target and spec)
MeanCustomerSpecification
1s
2s
3s
3s
Defects
Before
Mean CustomerSpecification
After2s
6s
6sNo Defects!1s
3s4s
5s
A 6s process
So what are we going to do?
• We are going to apply DMAIC (Define Measure Analyze Improve Control) to the experience of going to Starbucks
About Starbucks
• Founded 1971, in Seattle’s Pike Place Market. Original name of company was Starbucks Coffee, Tea and Spices, later changed to Starbucks Coffee Company.
• In United States:– 50 states, plus the District of Columbia– 7,087 Company-operated stores– 4,081 Licensed stores
?
SQC Guest
Define
What is Quality?– Dictionary Definition
1. a distinguishing characteristic, property, or attribute2. the basic character or nature of something3. a trait or feature of personality4. degree or standard of excellence, esp a high standard5. (formerly) high social status or the distinction associated with it6. musical tone colour; timbre7. logic the characteristic of a proposition that is dependent on
whether it is affirmative or negative8. phonetics the distinctive character of a vowel,
– Joseph Juran - > "fitness for intended use" – W. Edwards Deming -> "meeting or exceeding customer
expectations."
What is Critical To Quality?
• What is important to your customer?• What will delight or excite them?• What are the hygiene factors?
• These are things that have a direct and significant impact on its actual or perceived quality.
How do move beyond Brainstorming?
• Nominal Group -> when individuals over power a group
• Multi-Voting -> Reduce a large list of items to a workable number quickly
• Affinity Diagram -> Group solutions• Force Field Analysis -> Overcome Resistance to
Change• Tree Diagram -> Breaks complex into simple• Cause- Effect Diagram -> identify root causes
Nominal Group Technique
• A brainstorming technique that is used when some group members are more vocal then others and encourages equal participation
Page 114
Nominal Group Procedure
1. Team Leader Selected2. Individuals Brainstorm for 10-15 minutes
without talking. Ideas are written down3. Round Robin each team member reads idea
and it is recorded by the team leader. There is no discussion of ideas.
4. Once all ideas are recorded discussion begins
Multi-Voting
• Multi-voting is a group decision-making technique used to reduce a long list of items to a manageable number by means of a structured series of votes
Page 87
Multi-Voting Procedure
1. Develop a Large Group Brainstormed list2. Assign a letter to each item3. Each team member votes for their top 1/3 of
ideas.4. Votes are tallied 5. Eliminate all items receiving less than N votes
(rule of thumb 3)6. Repeat voting until there are ~4 items left
Multi-Voting Example
Affinity Diagrams
• A tool that gathers large amounts of language data (ideas, opinions, issues) and organizes them into groupings based on their natural relationships
Page 92
Affinity Diagram Procedure
1. Record Ideas on Post It Notes2. Randomize Ideas Together3. Sort Ideas into Related Groups4. Create Header Card5. Record Results
Affinity Diagram Example1. Randomize Ideas Together 2. Group Ideas
3. Create Headers4. Put it Together
Force Field Analysis
• Is a method for listing, discussing, and assessing the various forces for and against a proposed change. It helps to look at the big picture by analyzing all of the forces impacting on the change and weighing up the pros and cons.
Page 109
Force Field Procedure
1. Draw a large letter t2. At the top of the t, write the issue or problem3. At the far right of the top of t write the ideal state you wish
to obtain4. Fill in the chart
– List internal and external factors advancing towards the ideal state– List forces stopping you from obtaining the ideal state
Force Field Example
Tree Diagram
• Tree diagrams help link a task’s overall goals and sub-goals, and helps make complex tasks more visually manageable. Accomplished through successive steps digging into deeper detail.
Page 124
Tree Diagram Procedure
1. Identify the Goal2. Generate Tree Headings (Sub Goals)
– ~5 slightly more specific topics that are related to the general goal
– Place them horizontally on post it notes horizontally under goal
3. Generate Branches of sub goals as needed4. Record the results
Tree Diagram Example
Cause and Effect Diagram(Fishbone or Ishikawa Diagram)
• Is a tool that helps identify, sort, and display possible causes of a specific problem or quality characteristic. It graphically illustrates the relationship between a given outcome and all the factors that influence the outcome.
Page 97
Cause and Effect Procedure
1. Identify and Define the Effect2. Draw the Fishbone Diagram
– Place Effect as the Head of the fish
3. Identify categories for the main causes of the effect or use the standard ones (Man, Machine, Methods, Materials, Measurements, Mother Nature)
4. Add causes to the categories5. Add increasing detail to describe the cause
Cause and Effect ExampleGeneric Format 1. Identify Categories
2. Add Causes 3. Add Details
Now Apply It!
• Divide yourself into 6 Groups– Group 1- Nominal Group– Group 2- Multi-Voting– Group 3- Affinity Diagrams– Group 4- Force Field Analysis– Group 5- Tree Diagram– Group 6- Cause and Effect Diagram (What Causes a Bad
Cup of Coffee)• Solve the problem “What Makes a Quality Coffee
Experience?”
SQC Guest
Measure
Types of Data• Attribute / Discrete Data– Individual unit categorized into a
classification. Examples:• Counts or frequencies of occurrence
(# of errors, # of units)• Categories (good/bad, pass/fail,
low/medium/high)• Characteristics (locations, shift #,
male/female)• Groups (complaint codes, error codes,
problem type)– Finite number of values is possible– Cannot be subdivided meaningfully
Variable / Continuous Data Individual unit can be measured on
a continuum or scale Examples: • Length• Volume• Time• Size• Width• Pressure • Temperature• Thickness
Can have almost any numeric value Can be meaningfully subdivided
into finer increments
Page 110
44
Data Type – Why is this important?
Variable / Continuous Data• More analysis tools available• Smaller sample size needed• Higher confidence in results• To see variation, you can also
look at the distribution
Attribute / Discrete Data Requires larger sample size Usually readily available To see variation you stratify
0%
20%
40%
60%
80%
100%
FM OD ID Burr
1
0%
1%
2%
3%
4%
Days
% Defective
Data type is a key driver of your Project Strategy
Control Chartfor Individuals
Pareto Chart
Dotplot Histogram
160140120100806040
Median
Mean
1201101009080
Anderson-Darling Normality Test
Variance 1048.78Skewness 0.00716Kurtosis -1.63184N 500
Minimum 41.77
A-Squared
1st Quartile 68.69Median 104.203rd Quartile 130.81Maximum 162.82
95% Confidence Interval for Mean
97.15
27.11
102.85
95% Confidence Interval for Median
82.78 117.66
95% Confidence Interval for StDev
30.49 34.53
P-Value < 0.005
Mean 100.00StDev 32.38
95% Confidence Intervals
Summary for Mystery
Descriptive Statistics
Week
Pro
port
ion
11/510/18/277/236/185/144/93/51/29
0.4
0.3
0.2
0.1
0.0
_P=0.1972
UCL=0.3539
LCL=0.0404
1
P Chart of Resolved
Tests performed with unequal sample sizes
Control Chart
1
0%
1%
2%
3%
4%
Days
% Defective
Individuals Chart
So how do we translate our CTQs Into Measurements?
Y into Y into x
From the Customer Means Something Internally
You Can Measure it`
• Quality Functional Deployment (House of Quality)
• “Whats into Hows”
46
What is Measurement System Analysis?• MSA = Measurement System Analysis
• Treats measurement as a process– Procedures
– Gages
– Fixtures and other equipment
– People
• Assesses adequacy of the measurement system
• Determines sources of variation
Page 188
So What are We Going To Measure?
– Taste (what is taste?)• pH• Total Dissolved Solids
– Blue Meter– Combined Meter
• Temperature• Conductivity
– Consistency• Weight of the beverage
Go Measure!
• Create the Following Control Charts– Group 1: Starbucks Regular Pike– Group 2: Starbucks Decaffeinated– Group 3: Dunkin Donuts Regular– Group 4: Dunkin Donuts Decaffeinated– Group 5: Starbucks Regular Blond– Group 6: Starbucks Regular Dark
So How Do We Display the Data?
• Dot Plot• Run Chart• Box Whisker Plot• CUSUM• EWMA• Scatter Diagrams• Pareto Charts
Box Plot (Box and Whisker Diagram)
• Is a graphic depiction of groups of numerical data through their five-number summaries: the smallest observation (sample minimum), lower quartile (Q1), median (Q2), upper quartile (Q3), and largest observation (sample maximum). A boxplot may also indicate which observations, if any, might be considered outliers.
Page 164
51
Control Chart• Time plot of data with Center Line (mean average) & Control Limits
– Control limits are based on actual process variation (Not specs!)• UCL = X-bar (i.e., data mean) + 3s; LCL = X-bar - 3s
10
15
20
25
30
35
40
0 5 10 15 20 25
Center Line (X-bar)
Upper Control Limit (UCL)
Lower Control Limit (LCL)
Voice Of the Process (X-bar, UCL, LCL are based on actual data!): Control Limits and Center Line reflect process variation and stability A process is predictable (stable) when data points vary randomly within control
limits. Referred to as a process “in control.”Page 110
Before Using Control Charts Check for Normality
Negative
Frequency
1801501209060300
250
200
150
100
50
0
Histogram of Negative
Positive
Frequency
300270240210180150
200
150
100
50
0
Histogram of Positive
Normal
Frequency
24021018015012090
100
80
60
40
20
0
Histogram of Normal
Normal
Perc
ent
25020015010050
99.9
99
95
90
80706050403020
10
5
1
0.1
Mean
0.328
168.0StDev 24.00N 500AD 0.418P-Value
Probability Plot of NormalNormal
Positive
Perc
ent
300250200150100
99.9
99
95
90
80706050403020
10
5
1
0.1
Mean
<0.005
168.0StDev 24.00N 500AD 46.489P-Value
Probability Plot of PositiveNormal
Negative
Perc
ent
250200150100500
99.9
99
95
90
80706050403020
10
5
1
0.1
Mean
<0.005
168.0StDev 24.00N 500AD 44.491P-Value
Probability Plot of NegativeNormal
Page 173
Attribute (discrete)Variable (continuous)What Type Of Data?
Data Collected In Groups or Individuals?
Counting Specific Defects or Defective Items?
GROUPS(Averages)(n>1)
INDIVIDUALVALUES(n=1)
X-Bar R (Means w/Range)X-Bar S (Means w/St Dev)
Individuals (I Chart)With Moving Range (I-MR)
SpecificTypes Of “Defects”
DefectiveItems
You can count only defects
You can count how many are bad and how many are good
Poisson Distribution Binomial Distribution
Area ofOpportunity Constant In Each SampleSize?
YESNO
c Chart oru Chart
u Chart
Constant Sample Size?
np Chart orp Chart
NO YES
p Chart
Control Chart Decision Tree
NOTE: X-Bar S is appropriate
for subgroup sizes of > 10
Page 110
I-MR
𝑈𝐶𝑙=𝐷4 𝑀𝑅
𝐿𝐶𝑙=𝐷3 𝑀𝑅
𝑈𝐶𝑙=𝑋+𝐸2 𝑀𝑅
L
Page 317
Used to monitor variables data from a business or industrial process for which it is impractical to use rational subgroups
The , and constants are from Appendix D (Page 369)
Interpretation
Now Apply it
• Create the Following Control Charts– Group 1: I Chart for pH– Group 2: I Chart for Temperature– Group 3: I Chart for TDS- blue– Group 4: I Chart for Weight– Group 5: I Chart for Conductivity– Group 6: I Chart for TDS - Combined
SQC Guest
Mapping The Process
What is a Process?
• A Process
• Remember “Verb-Noun Combination”
Graphically Presenting a Process
• Six Sigma – SIPOC– Process Mapping
• Lean– Value Stream Map
Let the Picture do the talking
Suppliers Inputs Process Outputs Customers (SIPOC)
• Is a high-level picture of a process that depicts how the given process is servicing the customer.
Page 51
SIPOC Procedure1. Agree to the name of the process. Use a Verb + Noun format (e.g.
Recruit Staff).2. Define the Outputs of the process. These are the tangible things that
the process produces (e.g. a report, or letter).3. Define the Customers of the process. These are the people who receive
the Outputs. Every Output should have a Customer.4. Define the Inputs to the process. These are the things that trigger the
process. They will often be tangible (e.g. a customer request)5. Define the Suppliers to the process. These are the people who supply
the inputs. Every input should have a Supplier. In some “end-to-end” processes, the supplier and the customer may be the same person.
6. Define the sub-processes that make up the process. These are the activities that are carried out to convert the inputs into outputs. They will form the basis of a process map.
SIPOC Symbols• Suppliers: The individuals, departments, or organizations that
provide the materials, information, or resources that are worked on in the process being analyzed
• Inputs: The information or materials provided by the suppliers. Inputs are transformed, consumed, or otherwise used by the process (materials, forms, information, etc.)
• Process: The macro steps (typically 4-6) or tasks that transform the inputs into outputs: the final products or services
• Outputs: The products or services that result from the process.
SIPOC Example
Process Maps
• Are a graphical outline or schematic drawing of the process to be measured and improve.
Page 128
Process Map Procedure
1. Identify the process to be studied, identify boundaries and interfaces
2. Determine Various Steps in the process3. Build the Sequence of Steps4. Draw the formal chart with process map5. Verify Completeness
Process Map Symbols
Process Map Example
Value Stream Mapping (VSM)
• Special type of flow chart that uses symbols known as "the language of Lean" to depict and improve the flow of inventory and information
• Purpose– Provide optimum value to the customer through a
complete value creation process with minimum waste
Page 24
VSM Procedure
Before doing any steps, determine who owns the process!1. Identify Process Customers (Y Process Output Measures)2. Identify Process Suppliers 3. Map the Material (Process) Flow
• Process General Steps• Queue or Staging Areas
4. Identify Process Information Systems5. Map the Information Flow6. Identify Common Data7. Gather the Data
70
Common VSM Symbols
MSD Cust. Srvc.
Customer
MRP
ProductionControl
Electronic Communication Information Flow
Red Box and Rectangle represents information system used.
Dotted Line represents manual process connection
Box with Jagged top represents interaction with customer or supplier.
Block represents a process step that is performed.
Manual Information Flow
Determine Process Cycle Times & Identify Value Added Steps
VA
NVA
Value Added Steps are anything that the customer is willing to pay for
VSM Example
Links to the Videos
• Latte : http://youtu.be/HyAAxMEdB24
• Frap : http://youtu.be/3qk28eEbfc4
• Drip : http://youtu.be/IGuwC1WcjKY
• Clover : http://youtu.be/YtXClUKhLmw
Now Apply It!
• Graphically Depict the following– Group 1: Process Map Latte– Group 2: Process Map Frap– Group 3: Process Map Drip Coffee– Group 4: Process Map Clover– Group 5: SIPOC for Frap– Group 6: SIPOC for Clover
SQC Guest
Analyze
76
Steps in Test of Hypothesis1. Formulate the Null and Alternate Hypothesis2. Determine the appropriate test 3. Establish the level of significance:α4. Determine whether to use a one tail or two tail test5. Determine the degree of freedom6. Calculate the test statistic7. Compare computed test statistic against a tabled/critical
value
• Remember: tests DON’T PROVE anything. – They gather sufficient evidence against the null hypothesis Ho
or fail to gather sufficient evidence against Ho.
Determine The Appropriate Test• Z
– is any statistical test for which the distribution of the test statistic under the null hypothesis can be approximated by a normal distribution.
• T– is any statistical hypothesis test in which the test statistic follows a
Student's t distribution if the null hypothesis is supported• Paired T
– is a test that the differences between the two observations is 0• ANOVA
– Is a test to determine the differences between two or more treatments• Chi Squared
– Is a test to determine the goodness of fit of data to a distribution• Lots of Other Tests
78
Compare the observed test statistic with the critical value
| Ztest | > | Zcrit | Þ HA
| Ztest | £ | Zcrit | Þ H0
Zcrit-Zcrit
H0HA HA
79
| Ztest | > | 1.96 | Þ HA
| Ztest | £ | 1.96 | Þ H0
Compare the observed test statistic with the critical value
1.96-1.96H0
HA HA
80
Compare the observed test statistic with the critical value (1 Tail)
Ztest > 1.645 Þ HA
Ztest £ 1.645 Þ H0
1.645H0
HA
81
p-value
• p-value is the probability of getting a value of the test
statistic as extreme as or more extreme than that observed
by chance alone, if the null hypothesis H0, is true.
• It is the probability of wrongly rejecting the null
hypothesis if it is in fact true
• It is equal to the significance level of the test for which
we would only just reject the null hypothesis
Purpose of ANOVA • Use one-way Analysis of Variance to test when the mean of a
variable (Dependent variable) differs among two or more groups– For example, compare whether systolic blood pressure differs
between a control group and two treatment groups• One-way ANOVA compares two or more groups defined by a
single factor. – For example, you might compare control, with drug treatment with
drug treatment plus antagonist. Or might compare control with five different treatments.
• Some experiments involve more than one factor. These data need to be analyzed by two-way ANOVA or Factorial ANOVA.– For example, you might compare the effects of three different drugs
administered at two times. There are two factors in that experiment: Drug treatment and time.
83
Test Statistic in ANOVA• F = Between group variability / Within group variability
– The source of Within group variability is the individual differences.
– The source of Between group variability is effect of independent or grouping variables.
– Within group variability is sampling error across the cases – Between group variability is effect of independent groups or
variables
84
ANOVA is Appropriate if:• Independent random samples have been taken from each population• Dependent variable population are normally distributed (ANOVA is
robust with regards to this assumption)• Population variances are equal (ANOVA is robust with regards to this
assumption)• Subjects in each group have been independently sampled
85
ANOVA Hypothesis
• Ho: 1 = 2 = 3 = 4
Where• 1 = population mean for group 1• 2 = population mean for group 2• 3 = population mean for group 3• 4 = population mean for group 4
• H1 = not Ho
ANOVA Compare the Computed Test Statistic Against a Tabled Value
• α = .05• If Ftest > FCritcal Reject H0
• If Ftest <= FCritcal Can not Reject H0
Excel is very nice and does it for us!
Now we Are going to Apply ANOVA to Your Data
• Is there Difference Between Starbucks and Dunkin Donuts? pH? TDS? Conductivity?
• Is there Difference Between decaffeinated and Regular? pH? TDS? Conductivity?
• Is there Difference Between Different Starbucks Roasts? pH? TDS? Conductivity?
SQC Guest
Conclusion
Takeaways
• Industrial Engineering is focused on solving problems in:– Manufacturing– Finance– Logistics– Medical– Services (including Education)
• Six Sigma is one of many tools to solve problems
ASQ Greenbelt
• 100 Multiple Choice Questions• 4 Hours• Open Book, Open Notes *No Sample
Problems*• No graphing calculators allowed• Results Posted online 7-10 Days after
Requirements to Sit for the Exam• Required Experience
– The Six Sigma Green Belt requires three years* of work experience in one or more areas of the Six Sigma Green Belt Body of Knowledge.
• Minimum Expectations for a Certified Six Sigma Green Belt– Operates in support of or under the supervision of a Six Sigma Black Belt– Analyzes and solves quality problems– Involved in quality improvement projects– Participated in a project, but has not led a project– Has at least three years of work experience– Has ability to demonstrate their knowledge of Six Sigma tools and processes
* The Body of Knowledge is very broad it can be accessed at (http://prdweb.asq.org/certification/control/six-sigma-green-belt/bok). For Juniors and Seniors in ISE your course work counts. Others consider course work, internships and work experience to meet the requirement.
About the Course
• 11 Weekly Sessions starting the Week of 9/17 for the December 1st exam
• Purpose is to train students to pass the exam• Currently Schedule for Monday Nights. If > 25
students register additional sections will be added on Wednesday or Thursday
• Text Book – Certified Six Sigma Handbook
Certification Cost
• Exam Preparation = $296 includes
– ASQ Student Membership - $27– Six Sigma Greenbelt Course- $179 – Textbook - $90
• Exam Fee = $199• Total Certification Cost $495
More Information @ www.ASQPrinceton.org
My Contact Information
• Brandon Theiss– [email protected]– Connect to me on LinkedIn
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