© JD Consulting, 2006 Root Cause Analysis ASQ – Orange Empire Section 0701 by: Jack Dhuwalia, MS, MBA, DTM President, J D Consulting July 22, 2006
Jun 19, 2015
© JD Consulting, 2006
Root Cause Analysis
ASQ – Orange Empire Section 0701
by: Jack Dhuwalia,
MS, MBA, DTM
President,
J D Consulting
July 22, 2006
© JD Consulting, 2006 4
We’ll cover
• A Case Study
• Overview
• Key Ideas
• Defect (elusive)
• Jack’s Troubleshooting Concepts
• Methods - Tools
• More Case Studies
• Takeaways
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Case Study
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Slippery When Wet
• Identify and break into teams -regroup
• Hand-outs
• Problem statement (P1)
• Situation (P2)
• Background (P3&4)
• Go for it!
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What really happens
(undesirable stuff)?
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Top five issues with Problem
Solving• Experienced people not available
• Unable to identify root cause
• Solving the wrong problem
• Solutions creating more problems
• Demoralizing to employees
Bailing Water
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Key Ideas
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Hidden Causes
BO
P
BO
P
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Defect (elusive)
Defect Rate VS. Ease of
Discovering Cause
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Jack’s Troubleshooting Concepts
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Teamwork
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Human Nature
• Denial
• Blind spots
• They can’t “see” the problem
• Likely to miss the cause(s)
The same mind that creates a given
problem simply cannot fix the problem.
—Jack Dhuwalia
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for better results!
Invite an Outside Expert
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efine problem
nvestigate
dentify potential cause(s)
ort
onfirm assumptions
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Methods - Tools
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Methods for Investigations,
Data Collection And Analysis• Fish-Bone
• Flow Charts
• FMEA
• Control charts
• Pareto Charts
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More Methods…
• Capability studies
• Experimentation
• DOE
• 5 W’s
• Many more…
• Analytical trouble-shooting
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Fish-Bone
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Fish-Bone (contd.)
Label each ""bone" of the "fish". The major categories are:
The 4 M’s:
Methods, Machines, Materials, Manpower
The 4 P’s:
Place, Procedure, People, Policies
The 4 S’s:
Surroundings, Suppliers, Systems, Skills
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Flow Chart Product ready to
package
Product release
for sale
QC release
Sterilization
Fig. II Modified Process Flow
Take
corrective
action
Package sealing
operation
Test "empty"
packages at the
start
Seal meets
specs?
Test "empty"
packages at the
end
Seal meets
specs?
Yes
Yes
No
No
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FMEA
#
Proce
ss
step/FUNCTIO
N
Potential
Failure
Mode
POTENTIA
L EFFECTS
OF
FAILURE
Potential
Causes
of
Failure
CURRENT
PROCESS
CONTROLS
Before
MitigationAfter Mitigation
O
c
c
u
r
r
e
n
c
e
S
e
v
e
ri
t
y
D
e
t
e
c
ti
o
n
R
P
N
Mitigations
O
c
c
u
r
r
e
n
c
e
S
e
v
e
ri
t
y
D
e
t
e
c
t
i
o
n
R
P
N
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Control Chart
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Pareto Chart
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Analytical Trouble Shooting
• KEPNER TREGOE® – taught in 1974
• Systematic way of analyzing and trouble shooting
• Underlying principle: cause and effect
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ATS Concepts
• Historic, demonstratable relations ship exists between cause and effect
• Effect to be explained is always a Deviation
• Deviation can only be recognized in relation to a specific Should or expectation of performance
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ATS Concepts (contd.)
• Cause of a Deviation is always a change of some kind. No change – no Deviation
• Cause of a Deviation matches the Deviation it produces exactly
• Action required to control an event rests in knowing just how the cause relates to the condition it creates
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Cause and Effect
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ATS Process (contd.)
1. Identify the Deviation
2. Specify the Deviation
• WHAT
• WHERE
• WHEN
• EXTENT (HOW MANY)
3. Define Boundaries
• DEVIATION IS AND IS NOT
4. Examine the Distinctions
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ATS Process (contd.)
5. Look for Changes
6. Statement of Cause
7. Testing for Cause
8. Verifying the Cause
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ATS Process Questions
• Difference• What is different
• Odd
• Unusual
• Peculiar/distinct
– About IS as compared to IS NOT
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ATS Process (contd.)
Defining the boundaries of Deviation
Deviation IS Deviation IS NOT
What
Where
When
Extent
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ATS Process Questions (contd.)
• Change
– What has changed in, about, or around the difference?
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ATS Process Questions (contd.)
• Possible cause
– How could this change possibly cause the trouble or what is there about this change that could cause the trouble?
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ATS Process Questions (contd.)
• Most probable cause (test)
– If XYZ is the cause, how does it explain the IS and IS NOT facts?
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ATS Process Questions (contd.)
• Verify
– Does it check-out in real life?
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Process
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Case Study
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SWW ATS Process
• Observations
– DOE was getting “nowhere”
– Needed fresh, ATS approach
– No one really had the entire picture
– Not enough time to really understand history, what changed, etc.
– I had to take risks – stuck my neck out
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SWW ATS Process (contd.)
• Difference
– Odd/unusual that the reactor was completely agitated/mixed so variation could not be explained in the reactor
– Had to be before
• Action
– Flow chart
– Understand the steps
– Decided to test (2/day)
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ATS (contd.)
Figure II - Process Flow Chart
for PTCA Balloon Catheter
1. Tubing
Extrusion
6. Balloon
Bonding on
Catheter
5. Balloon Molding
4. Tubing Cutting
3. Irradiation
Testing
2. Gamma
Irradiation
7. Coating
Process (several
steps)
8. Catheter
Finishing
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SWW ATS Process (contd.)
• Tests – ROUND 1
1. Tubing alone (Step 4)
2. Tubing after Balloon Molding (Step 5)
3. Tubing with blown balloon (Step 5)
4. Bonded balloon (Step 6)
5. All coated at the same time
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SWW ATS Process (contd.)
• Test results
1. The coating process: “that ain’t it!”
2. Ability to accept coating is a function of the tubing/balloon surface (substrate)
3. Coating thickness appears to be a function of location (see diagram)
4. Conclusion: It is not the coating process!
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SWW ATS Process (contd.)
• Statement of cause
1. Tubing location seem to cause variation in coating thickness
2. Conjecture: heat history of substrate causes variation in coating thickness
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SWW ATS Process (contd.)
• Tests – ROUND 2
1. Tubing with blown balloon (Step 5)
2. Same as above at higher temperature
3. Same as above at lower temperature
4. All coated at the same time
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SWW ATS Process Conclusion
• Results – ROUND 2
1. Higher the vertical location, thicker the coating
2. Conclusion: Coating thickness variation is caused by thermal history of the balloon
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SWW ATS Process Verification
• Verification
– Similar results with different balloon lots
– Conclusion: Material Lots do not cause coating variation
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SWW ATS Process Corrective
Action• Corrective Action
– Turn the mold upside-down (see diagram)
• Verify Corrective Action
– Worked like “magic”
– Better coated balloon
– Better for the customer
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More Case Studies
• Painted aircraft component
• Empowerment: Sterile packaging for radioactive “seeds”
• Artificial Kidney Seal Rings
Key Ideas
• Cause(s) usually hidden
• Cause(s) not necessarily the “usual suspects”
• More than one cause(s) and/or condition
Jack’s Troubleshooting Concepts
• Team work
• Use appropriate tool(s)
• Invite an outside expert
© JD Consulting, 2006
Root Cause Analysis
ASQ – Orange Empire Section 0701
by: Jack Dhuwalia,
MS, MBA, DTM
President,
J D Consulting
July 22, 2006