Expert Problem Solving: Using Logic Trees for Root Cause Analysis

Copyright © Leanmap
Expert Problem Solving
Root Cause Analysis with Logic Trees
Introduction

Faults and Failures in the Office
Out of paper
Document error
Pending decision
Application frozen
Orders awaiting processing
Supply shortage
Ownership undefined
Network lost
Database outdated
Staff absent
Excess items
Backlog
Process unclear

Faults and Failures in the Factory
Abnormality
undetected
Humidity
exceeds limit
Process
failure
Excess
materials
Quality
rejects
Program
error
Package
jammed
Wrong item
loaded
Operator
unqualified
Machine down,
awaiting repair
Instructions
missing

Expert Problem-Solving – Introduction
• Disasters and repeat failures usually originate from a series of small problems that were identified
but never resolved due to incorrect analysis, incomplete understanding, or ineffective actions.
• The expert course builds the skills to analyze and solve complex problems, reducing the number of
issues, incidents, losses and complaints that impact people, profit, planet (3P bottom line).
• Learn how to systematically identify cause-effect relationships to create a shared vision among
stakeholders (investors, customers, employees), leading to focused action on controllable causes.
• Insights from the structured analysis allows addressing root causes far upstream, while improving
detection capabilities that prevent further escapes, making the system immune to failure.
• Roles include sponsor, student, coach. The sponsor allocates resources and provides context, such
as a major incident, unhappy customers, or identified losses. The student invests time to analyze the
problem and implement solutions. The coach evaluates progress, provides advice and feedback.
• Completing the expert course not only builds new skills, but also creates a better understanding of
the causal relationships that drive business performance and customer satisfaction.
• What’s the cost of failure? What’s the benefit of a solution? Any major failure prevented, and any
repetitive problem permanently solved makes a positive contribution to the bottom line.
The financial benefit is $5k…50k for 90% of evaluated problem-solving cases (n=67).

The 8 Factors
Placing blame or shifting the problem to an external party Owning the process until defined goals are truly achieved
Trying to solve complex problems with simple tools: 5-why Solving complex problems using appropriate tools: logic tree
Stopping too soon, before uncovering the underlying causes Stopping only at a desired, uncontrollable, or root cause
Believing there is just one mythical cause that explains it all Accepting an infinite set of causes for any given problem
Categorizing causes or picking them from a menu of causes Accepting each problem is unique, not taking shortcuts
Using non-actionable causes, “insufficient” or “inadequate” Overcoming our own ignorance by investigating further
Having different opinions or solutions for the same problem Creating a single reality that all stakeholders agree with
Telling stories, starting from past, ending with the problem Identifying causal relationships, from problem to its causes
SuccessFailure

The Titanic Tragedy
Newspapers reported facts and provided a simplistic cause-effect analysis, why the Titanic sunk:
• Titanic began its maiden voyage to New York at noon on April 10, 1912, from Southampton, England.
• On night of April 14, at 11:40pm, crew sighted an iceberg immediately ahead of ship.
• In about 40 seconds it collided with an iceberg estimated to have a gross weight of 150,000-300,000 tons.
• Iceberg struck the Titanic near bow and raked side of ship's hull damaging hull plates and popping rivets.
• At 2:20am, April 15, 1912, Titanic sank within 2 hours and 40 minutes, with the loss of more than 1500 lives.
Ship collided
with iceberg
Over 1500
lives lost

1500 Lives lost
People
in water
Ship
sinks
Bulkheads
not sealed
Ship hit
iceberg
High speed
18 knots
Small rudder
size
See iceberg
late
Bulkheads
stop flooding
Prioritize comfort .
over safety
!
✓
Water fills
entire hull
Ship in water
Cut hull open
✓
Insufficient
lifeboat drills
Prioritize leisure .
over safety
!
?
Speed record
expected
Prioritize speed
over safety
?
✓
North Atlantic
is fastest route
Select
fasted route
✓
Short sight
at night
Lookout not
using binoculars !
✓
Speed record
expected
Prioritize speed
over safety
?
✓
Capability
of ship
Decision to
go full speed
✓
Low turbulence
from small size
Design rudder
to speed
✓
✓
Insufficient
lifeboats
Transporting
passengers
Fill boats only
at half capacity
✓
Risk analysis
not performed
Decide based
on assumption
?
!
Advances in
technology
Belief of
unsinkable
Reduce lifeboat
requirements
✓
?
Steel plates
buckled
Fail to validate
High slug
concentration
!
?
Rivets join
steel plates
Rivets brittle
fracture
✓
Low
temperature
Low
steel quality
Apply
high stress
✓
✓
North Atlantic
current
Decide to
enter ice field
✓
Iceberg
present
Ship crossing
Atlantic
Maneuver
ineffective
✓
Lax maritime
regulations
Prioritize open
view over safety !
Titanic Reality Tree
Action Cause Condition Cause
Desired or uncontrollable → Stop
Need more information → Check
Identified Root Cause → Act
✓
?
!
Download: leanmap.com/shop

Conditions + Action = Effect
Matches
Available
Strike
Match
Open
Flame
Oxygen
Present
ActionCondition Condition
Effect

Conditions + Action = Effect
Paint + Canvas = Art+ Painting

The 11 Foot Bridge
Copyright Jürgen Henn – 11foot8.com – used with permission
Ignore Sign
Crash Truck
Low Bridge
Durham, North Carolina, USA

Solving Complex Problems
Event-Based Problems
• Disaster
• Accident
• Breakdown
• Risks
• Delays
• Defects
Rule-Based Problems Human Failures
• Errors
• Mistakes
• Violations

The 3 Types of Causes
Physical Causes – What?
Technical Reason for Failure
1
Human Causes – How?
Non-Performance or Non-Compliance
2
Latent Causes – Why?
Deficiency in Management System
3

0.74% Patients Receive Incorrect Insulin Dose
Insulin Dose
Incorrect
p = 0.00741
Problem
Programming
Failure
p = 0.01
Verification
Step Skipped
p = 0.4
No Backup
Power Used
p = 0.8
AND
x
Human Causes – How?
Incorrect Sugar
Level Measured
p = 0.00281
Correct Dose at
Wrong Time
p = 0.00408
Delivery System
Failure
p = 0.00052
Sensor
Failure
p = 0.002
Computation
Error
p = 0.00001
Timing
Failure
p = 0.004
Timer
Reset
p = 0.00008
Incorrect Insulin
Computation
p = 0.00011
Incorrect Pump
Signal
p = 0.00007
Pump
Failure
p = 0.00034
Power
Outage
p = 0.0001
OR
+
OR
+
OR
+
OR
+
AND
x
Transmitter
Failure
p = 0.0008
Physical Causes – What?
Pending
Investigation
Untrained
p = 0.5
Distracted
p = 0.2
OR
+
Careless
p = 0.1
Overconfidence
p = 0.3
Untrained
p = 0.1
OR
+
Latent Causes – Why?

The 8 Types of Human Failure
Human Failure
Not meeting needs
Routine Violation
“It’s normal”
5
Situational Violation
“No choice”
6
Exceptional Violation
“Emergency”
7
Human Error
Wrong planning or doing
Action Slip
“Mishap”
1
Memory Lapse
“Forgot”
2
Rule Mistake
“Thought it’s right”
3
Knowledge Mistake
“Didn’t know”
4
Acts of Sabotage
“Fight back”
8out of scope
Action Error
Not as planned
Non-Performance
Unintentional failure
Non-Compliance
Intentional failure
Violation
Breaking rules or promises
Thinking Error
Action as planned

Solving Complex Problems
1. Problem 2. Analysis 3. Evidence 4. Causes 5. Solutions
1. Understand causal relationships
2. Identify controllable causes
3. Implement effective solutions

1. Complete the Course
2. Apply Your Knowledge
3. Earn Your Certificate
leanmap.com/academy

Expert Problem Solving: Using Logic Trees for Root Cause Analysis

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