Total Quality Management
CS3300
Fall 2015
A long time ago
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Made in Japan – then and now
W. Edwards Demming
We improve product by improving the process, not by testing the
product
YOU DO NOT TEST QUALITY IN, YOU DESIGN IT IN.
Total Quality Management
TQM
Customer Satisfaction
100% Compliance with Expectations
Red Bead Experiment
https://www.youtube.com/watch?v=ckBfbvOXDvU
Deming's 14 Points
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Create a constancy of purpose for improvement of product and
service.
Adopt the new philosophy.
Cease dependence on mass inspection
Do not award business on price alone
Improve constantly and forever the system of production and
service
Institute training
Adopt and institute leadership
Demings 14 Points
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Drive out fear
Break down barriers between staff areas
Eliminate slogans, exhortations, and targets for the work force
Remove barriers that rob people of pride of workmanship
Encourage education and self-improvement for everyone
Take action to accomplish the transformation
Continuous Process
Improvement
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Shewart Cycle
Plan – Do – Check – Act (PDCA)
Too often – ACT...
Statistical Process Control
Seven Basic Tools
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Pareto Charts
Ishikawa Diagrams
Control (Run) Charts
Histograms
Scatter Charts
Checksheets
Flow Charts
Raw Data (Ordered)
Module
Time
Cumul
Percent
icongen
42.2
42.2
34
hud_ipc
40.8
83.0
67
huddsply
18.5
101.5
82
hud_proc
15.0
116.5
94
hud_boot
7.0
123.5
100
Pareto Example
82%
67%
Percent of Total
Time Worked (Hours)
N=123.5
100%
96%
34%
42.2
40.8
18.5
icongen
hud_ipc
huddsply
15
hud_proc
7
hud_boot
Using all that PSP defect data
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First plot the defects by category on the pareto chart
We always want to work on the most problematic area first.
We are trying to id the 20% of things that are causing us 80% of the
trouble
Defect Categories
10 Documentation problem
20 Syntax
30 Build
40 Assignment
50 Interface
60 Error Handling
70 Data
80 Function
90 System
100 Environment
Ishikawa Diagrams
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AKA Cause-Effect, fishbone Diagram
Root Cause Analysis
Don’t treat symptoms!
Uses diagram plus brainstorming
4 M’s: Manpower, Machines, Methods,Materials
4 P’s: Policies, Procedures, People, Plant
Basic Syntax
Environment
Process
WHY???
Symptom/
Problem
Equipment
People
Example Ishikawa
Measurement
Poor change tracking
People
Inexperienced manager
Inexperienced developers
Icongen used 34%
of all effort
Poor IDE
Hard to modify
Bad design
Equipment
Process
Formulate the PDCA Plan
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Look at the Ishikawa diagram and select the most probable root
cause
Make a plan to eliminate that issue
Try it on a small scale
Take more measurements
If improved, then adopt, otherwise reject
Processes and control
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To be improved a process must be repeatable
To be repeatable it must produce the same results each time
Variation must be predictable
Histograms
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Graphical representation of variation and distribution
Determine range of values (highest – lowest)
Divide data into groups
Width of group = range / number of groups
Draw table of all values
Interpretation
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Normal distribution – expected in usual case.
Bi-modal – two process at work or a process that has changed over
time, or input from 2 sources like different shifts.
Skewed – there is a limit to the process – artificial or natural
Truncated – outside limit (usually from a supplier)
Control Charts
• Variation of run chart
• Plot data first (run chart)
• Draw in control limits at 3*standard deviation
Control Chart Signals
• Point outside UCL/LCL
• 2 out of 3 successive values are on same side and more than 2
sd from centerline
• 4 out of 5 successive values are on same side and more than 1
sd from centerline
• 8 successive values on same side of centerline
From 4320 Homework
• You boss is concerned about the number of defects found by QA. He has
tasked you to look at improving the implementation process so that defect
rates are reduced. You currently track defects in the 10 PSP categories.
You gather raw defect counts and time to fix defects by category. The
following data is available:
Total Defects by Category:
10 Documentation
20 Syntax
30 Build
40 Assignment
50 Interface
60 Error Handling
70 Data
80 Function
90 System
100 Environment
35
140
23
81
100
200
74
79
32
56
Time Spent in Correction(Minutes):
500
200
60
300
1000
467
657
1324
326
23
CS4320 Homework
Select the area from part b, and determine the most likely probable root cause.
You are still unsure of the defect rates in your current process. You look at the raw defect numbers
for the last 150 weeks to see if a pattern exists.
Last 150 week numbers:
47 51 52 48 47 65 65 65 65 65 41 41
44 46 42 10 10 05 09 09 52 52 51 51
47 18 18 19 22 22 48 48 51 51 52 54
54 57 57 56 49 49 49 47 47 11 16 15
16 11 58 58 58 53 53 15 15 16 11 11
57 57 57 58 58 61 62 62 64 64 18 18
19 22 21 28 28 28 27 23 49 47 48 52
52 63 64 64 63 59 18 21 21 21 21 52
52 51 51 52 60 60 60 64 64 43 43 42
41 41 34 33 32 34 34 48 47 49 51 52
58 57 58 57 53 23 24 25 26 23 38 35
36 40 40 43 44 45 46 46 57 56 55 54
58 47 48 51 51 52
You decide to draw a histogram to determine if a normal distribution exists. (Use K=10). What does
this data tell you about defects in your organization?
Use the last 10 weeks of data from part d to draw a control chart of the total defects by week. Use a 2
Sigma control band. What does this chart tell you?
Six Sigma
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Developed by Motorola in 1986
Famous after Jack Welch used at GE in 1995
Process:
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Define Phase (id customer, critical quality requirement)
Measure Phase (Define goals, Data Collection plan, Collect needed
data, Variation in current process)
Analyze Phase (analyze data)
Improve Phase (id solutions, pilot solution)
Control Phase (implement process control)
The Big Problem -- Systems
• We don’t actually live in a linear world where cause and effect
is easy to see.
• Peter Senge : The Fifth Discipline
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Today’s problems are caused by yesterday’s solutions
The easy way out is often the way back in
The harder you push, the harder the System pushes back
Behavior grows better before it gets worse
The cure can be worse than the disease
Faster is slower
Cause and effect are not closely related in time and space
Small change can produce big results, but the leverage areas are
not always obvious
• You can have your cake and eat it too – but not all at once.
• Dividing an elephant in half does not make 2 small elephants
• There is no outside enemy, no one to blame
System Archetypes
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Balancing Process with Delay
Limits to Growth
Shifting the Burden
Eroding Goals
Escalation
Success to the Successful
Tragedy of the Commons
Fixes that Fail
Growth and Underinvestment