Root Cause Analysis Presentation
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Transcript of Root Cause Analysis Presentation
1Quality Tools
Root Cause Analysis
2
Root Cause Analysis
Module OutlineChronic vs. Sporadic Problems Improvement (Breakthrough) vs. TroubleshootingAddressing Chronic Problems - Breakthrough
DefinitionsDiagnosisWhy “Root Cause”?Tie to MBF (Management by Fact)
Addressing Sporadic Problems - Troubleshooting SummaryResources
?
3
Root Cause Analysis
Module Objectives You will be able to:• Distinguish between chronic vs. sporadic
problems.• Define Problem/Symptoms/Causes/Diagnosis.• Describe approaches to find root causes of chronic
problems.• Describe the link between Root Cause Analysis
and MBF.• Describe approaches to find root causes of
sporadic problems.
4
Root Cause Analysis
Improvement vs. Fire FightingPe
rfor
man
ce
Good
BadSporadic
ChronicGain
Time
5
Root Cause Analysis
Chronic Problems• Existed for some time• Usually “lived with” or accepted• Cost more $$$$$ than sporadic problems• Don’t sound alarms (allowances for problem have
been made in the system)• Competitors may be enduring same losses• Improvement is needed when a chronic problem
is occurring• Requires improvement PROJECTS - investment
of time and resources• Fire Prevention - attack the chronic level
6
Root Cause Analysis
Sporadic Problems• A “spike” in performance• “Alarm” usually goes off• Troubleshooting used when a sporadic problem
happens (a departure from the normal level)• Aimed at restoring the status quo• May include Interim (temporary) fixes• Corrective Action - eliminate the cause of the
problem• Remove the change that produced the deviation or
new change to offset deviation• Fire Fighting - focus on control
7
Root Cause Analysis
Improvement vs. TroubleshootingImprovement: Focused on attaining a new level
of performance that is superior to any previous level.
• Accomplished through BREAKTHROUGH.• Improves chronic level of performance.• Fire Prevention
Troubleshooting: Focused on solving a sudden change in performance.
• Accomplished with CORRECTIVEACTION to put out a fire.
• Improves sporadic level of performance.• Fire Fighting
8
Root Cause Analysis
Sequence for Breakthrough•Proving the need•Identifying Projects•Organizing project teams•Establishing project
(mission/vision/responsibilities)•Diagnosis - to find the causes•Developing remedies - based on knowledge of the causes•Proving remedies & effectiveness - under operating conditions•Dealing with resistance to change•Controlling at the new level
Set-
upC
arry
-out
9
Root Cause Analysis
DefinitionsProblem: Any deviation from the standard,
expected, or desired which is outside the accepted tolerance, norm, or benchmark.
Project: a problem scheduled for solution!Symptom: An observable indicator, cue, or event
directing attention to a problem. Arising from and accompanying a problem.
Theory: Unproved assertion as to reasons for the problem and symptoms.
10
Root Cause Analysis
Definitions - ContinuedCause: “Something” that happened to produce a
deviation of the actual from the expected or desired. Proved reason for existence of problem. Often “multiple causes”.
Dominant or Root Cause: a major contributor to existence of problem which must be fixed before there is an adequate solution.
Remedy: a change that can successfully eliminate or neutralize the cause of a problem.
11
Root Cause Analysis
Definition - DiagnosisDiagnosis: the process of studying symptoms,
theorizing as to causes, testing theories, and discovering causes.
• Diagnosis - to find the causes• Diagnostic Journey = “symptom to
cause”• Followed by Remedial Journey =
“cause to remedy”• “Symptom to cause” is DIFFICULT!
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Root Cause Analysis
Diagnosis for ImprovementDiagnostic Journey:1. Study the symptoms surrounding the problem to serve
as a basis for theorizing about causes.2. Theorize the causes of these symptoms.3. Collect data and do analysis to test the theories and
determine the causes.
When the problem can be switched on & off
at will - the journey is over!
13
Root Cause Analysis
Studying Symptoms• Two forms of “Evidence”:
1. Words/documentation describing problem2. Physical measurements & analysis of product/process
• Agreement on “terms/descriptions” for symptoms• Recording data - established to test specific theories• Quantifying symptoms:
•Frequency•Intensity
• Use of Pareto Charts/Analysis
14
Root Cause Analysis
Tools for Symptoms
Scratches IIII II II IIII I 15Runs IIII IIII IIII IIII IIII I IIII IIII 34Dirt IIII I IIII 11Wrong Color IIII I I 7Paint Peeling I I 2
Total 32 15 22 69
Problem TotalOrder 1 Order 2 Order 3
• Check Sheets• Concentration Diagram• “Autopsies”
• “Glossaries” for symptom terms
• Pareto AnalysisCheck Sheet Example:
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Root Cause Analysis
Theorizing Causes• Diagnosis is made theory by theory• Need to affirm or deny the validity of theories• This is “IDENTIFYING POTENTIAL CAUSES”• 3 Steps
1. Generate Theoriese.g. Brainstorm, Ask Why 5 times
2. Arrangement of Theoriese.g. Matrix, Tables, Cause & Effect Diagrams
3. Choosing Theories to be Testede.g. Data Collection, Pareto Analysis
• Establish Priorities for testing theories
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Root Cause Analysis
• Ask Why 5+ times• Brainstorming*• Cause & Effect Diagrams*• Force Field Analysis*• Affinity Diagram*• Structure Tree Diagram*• Interrelationship Digraph*• Program Decision Process
Chart (PDPC)*• Matrix Diagram*
• Check Sheet*• Pareto Analysis*• Designed Experiments• ETC.
Tools for Theorizing Causes
* Included in Memory Jogger II
Pareto Chart Example:
34 15 11 7 249.3 21.7 15.9 10.1 2.9
49.3 71.0 87.0 97.1 100.0
0
10
20
30
40
50
60
70
0
20
40
60
80
100
Defect
CountPercentCum %
Per
cent
Cou
nt
Paint Shop Defects
17
Root Cause Analysis
Tool Example - Ask Why 5 TimesFailures from Supplier A are 2X the industry average.
There is excessive damage in transit.
Packaging is insufficient.
Packaging specifications are incomplete.
Why?
Why?
Why?
Why?
Real Root Cause
There are no technical specifications for packaging available.
Why?
GenerateTheory:
Follow with Remedy!
18
Root Cause Analysis
Tool Example - Cause & EffectGenerate Theory:
Follow with Test of Theories based on priorities
Out of Date
Not Manufacturable
PartProblem
Cutting oilBar Stock
Capability
Scheduling
cpk Tolerances
Procedures
Set-upMaintenance
Cost
Inaccurate
TrainingEngineeringSupport Operator
Errors
Adjustments
Materials Machinery
Methods Manpower
WrongMaterial
OverSized
Wrong Oil
Packaging
PrintInaccurate
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Root Cause Analysis
Tool Example - Structure Tree
ElbowFailures
Crimp makesinadequate contact
Cross Thread
Pin not fullyseated
Cable not fullyseated
DefectiveElbow
Operator
Material
Methods
Tools &Equipment
Guide
Thread
Lack of Verificationfor Alignment
# of Revolutionsnot counted
Problem Subproblems TheoriesMost LikelyRoot Causes
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Root Cause Analysis
Testing Theories to Find Cause• Determine which cause is ROOT cause• Identifying most likely cause• DATA COLLECTION & ANALYSIS!• Methods
1. Product/Process “Dissection”e.g. Flow Map, Process Capability Study, Time to Time
2. Collecting New Datae.g. Measuring within the process
3. Experiments - create & process trials to test validitye.g. Designed experiments, pilots, trials
4. Measure for Diagnosise.g. Variables vs. attributes, increase precision, new
methods
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Root Cause Analysis
• Historical Review• Flow Diagram/Map*• Process Capability Analysis• Time to Time Analysis• Stream to Stream Analysis• Histograms*• Control Charts*• Piece to Piece Analysis• Within Piece to Piece Analysis• Multi-Vari Analysis
• Check Sheet*• Pareto Analysis*• Designed Experiments• Correlation Studies• Measurements within process• Study of Work Methods• Measurement Capability Studies• ETC.
Tools for Testing Theories
* Included in Memory Jogger II
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Root Cause Analysis
Tool Example - Histogram & Run Chart
Test Theory:
Follow with Remedy!
Monthly DPU for Product XYZ
0.00
5.00
10.00
15.00
20.00
25.00
Dec
-97
Feb-
98
Apr
-98
Jun-
98
Aug
-98
Oct
-98
Dec
-98
Feb-
99
Apr
-99
Jun-
99
Aug
-99
Oct
-99
Dec
-99
DPU
Level III Audit DPMU
0
500
1000
1500
2000
2500
3000
6/1/
98
6/3/
98
6/5/
98
6/9/
98
6/11
/98
6/15
/98
6/17
/98
6/19
/98
6/23
/98
6/25
/98
6/29
/98
DPM
U
Histograms:Run
Charts:
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Root Cause Analysis
Tool Example - CapabilityTest Theory: - Structured Experimentation
Follow with Remedy!
• Goal: Collect data on all parts of the process so that:– Capture all contributors to variability– Variability can be partitioned into parts due to each
contributor
=
Total Machine Cavity Time Sample
+ + +
24
Root Cause Analysis
Diagnosis of Failures in Systems• Historical Review - objective to improve segment of
system used to attain qualitye.g.: Product Development, Supplier Relations
• Based on analysis of # of past problems• Interview and Document:
1. Brief description of problem2. Stage where problem 1st observed3. Earliest stage at which problem COULD have been discovered4. Reasons for NOT discovering problem at earlier stage5. What could have been done to have found the problem earlier or avoided it completely
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Root Cause Analysis
Diagnosis of Failures in SystemsExamples:1. Historical review of past product development problems:• Symptoms & Cause: Review revealed use of
FMEA/FMECA (Failure Mode, Effect, and Criticality Analysis) would have identified problems upfront.
• Remedy: Require FMEA upfront for new products.
2. Historical review of manufacturing defects:• Symptoms & Cause: Review revealed lack of set-up
procedure led to high lot to lot variation and defects.• Remedy: Document and implement set-up procedure.
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Root Cause Analysis
Diagnostic JourneyRoot Cause AnalysisBegins with Collecting Data on Symptoms
Ends with agreement on Cause(s)
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Root Cause Analysis
Why Find the “Root Cause”?
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Root Cause Analysis
What is MBF Used For? Address gaps in business performance
— Customer Satisfaction— Employee Satisfaction— Business models— Operational processes— Manufacturing processes
Simplify reporting Link problems and root causes with action and
results Link a reporting format to a problem solving model Report on projects that address a specific problem
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Root Cause Analysis
Management by Fact (MBF)
DirectionSetting
DirectionDeployment
ManagementProcess
Policy Deployment &Management by Fact
PolicyDeployment
MonitorPerformance
GapDetected
No
Yes
PRIORITIZ AT ION &ROOT CAUSE
COUNTER M EASURES& ACTIV ITIES
W HO W HEN PROC ESSCAPABILITY
Process and Equipment1.1 1.1
Product Design2.1 2.1
M ethods3.1 3.1
People and Workmanship4.1 4.1
BENCHM ARK
Supplier5.1 5.1
Data Graph Supporting Data Graph
PROBLEM STATEMENT
Remedies
Root Cause AnalysisDiagnosis
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Root Cause Analysis
2. Root Cause Categorization / Analysis (RCA)
AnalyzeProblem
2
•Separate “beliefs” from “real” problem•Determine, categorize, and analyze Root Causes•Use basic quality tools
•Cause and Effect Diagram•Affinity diagram•Ask “WHY” 5 times
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Root Cause Analysis
MBF FormPROBLEM STATEMENT/OBJECTIVES & PERFORMANCE TRENDS: (indicate a brief statement of fact here)
Insert graph of performance over time here (e.g., Pareto Chart / Current State vs. Goal)
Insert graph of more detailed information here (Supportive Info. as necessary - e.g., Costs associated with the problem statement)
PRIORITIZATION & ROOT CAUSE(list the gaps in performance & state the true root cause)
COUNTER MEASURES & ACTIVITIES(enter specific action items, who has ownership and the due date)
WHO WHEN PROCESS CAPABILITY
1. Process and Equipment1.1 (ask the five whys to get to the root cause) 1.1 (solution path should focus on “Breakthrough Improvements”)
(Enter expectedbenefits for eachcounter measurehere.)
(Enter impact of eachcounter measurehere. Compare to seeif target wasachieved.)
2. Product Design2.12.2
2.12.2
3. Methods3.13.23.3
3.13.23.3
4. People and Workmanship4.1
4.1 BENCHMARK
5. Supplier5.15.2
5.15.2
(Use industry benchmarks here compared toour current state)
Root Cause Analysis/Diagnosis
Remedies
32
Root Cause Analysis
Troubleshooting• Diagnosis & remedial action applied to
sporadic problems• Generally receives immediate attention• Result of adverse change• Similar to chronic problem journey, but often
simpler• Journey is discovering what the change was
and removing or adjusting for it• Journey: Symptom to Cause to Remedy• If troubleshooting is ineffective, the result
will not be maintained
33
Root Cause Analysis
Troubleshooting• Ask: What, Where, When, How Much, Who• Compare Good vs. Bad, time to time, ETC.• Ask what “IS & IS NOT”• Reconstruct time sequence• Take corrective action to remedy the problem• Use a structured approach:
1. State deviation.2. Specify the deviation (is & is not, what, where, etc.).3. Identify unique characteristics of deviation.4. Search for changes.5. Develop possible causes.6. Test the possible causes against the requirement.7. Verify the cause (duplicate or eliminate by removing cause).
34
Root Cause Analysis
Summary• Need to distinguish between sporadic & chronic problems• Need to be persistent - get to root cause!• For chronic problems:
•Use BREAKTHROUGH•Use Root Cause Analysis (Diagnosis)
• For sporadic problems - use Troubleshooting• Improvement requires use of multiple quality tools!• To find true (root) causes you need to be a:
•Doctor•Detective•Driver
•Gardner•Firefighter
35
Root Cause Analysis
References•Books (+ many others):
– “Quality Planning and Analysis”, J. M. Juran & Frank M. Gryna, Third Edition, McGraw Hill.
– “Juran’s Quality Control Handbook” 4th Edition, McGraw Hill.
– The Memory Jogger II, Michael Brassard & Diane Ritter, GOAL/QPC, 1994.
– Analytic Trouble Shooting, Kepner Tregoe, 3rd Edition, 1978, Princeton Research Press