WHY - WHY ANALYSIS
TRAINING
OBJECTIVES:
To understand the definition of Why - Why Analysis.
To clarify the procedure for developing a Why - Why
Analysis.
To stress the importance of each step in the Why Why Analysis.
COURSE SCOPE / JUSTIFICATION:
Why-Why Analysis is a basic, fundamental tool in the
development of the IWS cornerstones, so it is essential
that each Leader in the implementation of IWS know
this technique and transmit it to his/her work teams.
WHY - WHY ANALYSIS
✻
What is Why-Why Analysis?
✻ It is a tool to identify root causes of a problem
so that countermeasures can be applied to
prevent reoccurence.
✻
Why-Why Process:
✻ Basically the process is to keep asking why
for all possible causes until you can find the
root cause for each effect and, therefore, find
a countermeasure for each root cause.
Why-Why Analysis
A different way to organize Cause and
effect relationships.
More efficient after a Cause and effect
Analysis
Done on the Priority items found in a
Cause and Effect Analysis.
How do tools fit?
HuMan
Machine
Effect
Material
Methods
EnvironMent
Cause and Effect Worksheet
Cause
Effect
Type of Check
Check Details
1. Direct Observation
Thesis
2. Evidence from collected data
3. Expert’s experience
4. Theory
5. Others
Already existing reference standard
Check method to be
used
Verify existence of cause and
effect for this situation
Already existing Control Method
Problem
Why
Why
Why
Why
Why
Results of the check
Recommneded Why-Why
Analysis Approach
Go On the Floor, at the point of the problem
See the problem
Listen to the people who live the problem
What is the Product of a Why-Why Analysis ?
It is a structured, field checked, relationship with each
cause-effect relationship linked from the lowest
element back
WHY-WHY
to the
P
Standards
Std.’ A A SOP
Why? F
h
T
A
(4M’s)
C s p c
phenomenon. e
C
R i
E
n
o
m
e
n
o
n
W
h
y
W W
h h
y y
?
?
?
W
a h
h o ue
y osle
t e c
dk
?
E
x
i
s
t
?
p
l
i
e
d
?
t a
i k
oe
nn
?
x
i
s
t
?
c
t
i
o
n
h
u
M
a
n
e
q
u
i
p
M
M
e
t
h
o
d
NTrue
NTrue
Y
True
N
Y
N
Restore
New
Std.
Y
N
X
New
Maint.
Std.
X
X
M
a
t
e
r
i
a
l
Let’s Break the Analysis
into the Following Steps
1. Understanding the Problem
2. Defining the Phenomenon to be analyzed.
3. Establishing Cause-Effect Relationship
through Why questioning and Field Checks.
4. Logical Review of the Analysis
5. Checking for Standards and SOP’s
1. Understanding the Problem
Let’s See What’s going on?
1. The light bulb
“doesn’t go on”
3. The match
“doesn’t light”
2. “He slipped”
4. The pen
“doesn’t
write”
Time: 10’
Understanding the problem
•
•
•
Form a team of qualified,
knowledgeable people.
Develop a general description of the
problem.
Develop an initial problem statement.
1. Understanding the Problem
How you focus on the
Problem Greatly impacts the
success of the Analysis.
1. Understanding the Problem
Two Clarifying approaches
a) According to the Process or Work Flow requirements.
b) According to the physical causes.
1. Understanding the Problem
According to Process or Work Flow requirements
Identify those conditions required by the
Process to correctly operate and check all of
them before start doing the analysis.
(Checklist)
Advantages:
+Simpler
+More practical
+Faster
1. Understanding the Problem
According to physical causes.
Identify the mechanics that generates the
phenomenon and start the analysis based on it.
Advantages:
+More complete
+More precise
+More effective
This material considers this
approach as the standard way to
perform why-why analysis.
2. Defining the Phenomenon to be analyzed.
Define the the Phenomenon
We intend to define the mechanics that
generate the phenomenon, in other words, the
way or process through which what we are
describing occurs.
Break the problem down into specific,
observable phenomena.
Align the team on what success looks like.
General Problem vs
Phenomenon
✻
General Problem
An intricate, unsettled question or issue
A source of perplexity or distress
Made up of many observable phenomenon
✻
Phenomena
Specific, observable facts or events
Problem vs Phenomenon Example
Problem: The room is too dark
Better: The light bulb “doesn’t go on”
Best: There is no flow of electric current through
the filament
Problem vs Phenomenon Examples
Examples
Process reliability is below 90%
The heat exchanger plates are cracked
The reactor pump seals leak
Product quality deviations are excessive
Bottle product labels are scratched
Bottle are being underfilled by 2 ounces per bottle
The family car is worn out
The engine is using one quart of oil every 500 miles
The car seats are ripped
Problems? Phenomena?
Scotoma Training
Definition
Scotoma literally means “limited vision within our
field of vision.” It is used to explain the fact that we
sometimes see what we expect to see.
How it links to this training
Scotomas can keep us from recognizing the
causes to some problems. We might not even
recognize the problem. (Like the way we overlook
defects if we have gotten to the point where we
consider them as normal.)
What’s the problem?
What’s the problem?
What’s the problem?
What’s the problem?
What’s the problem?
What does Success Look Like?
2. Defining the Phenomenon to be analyzed.
What’s going on?
Workgroup activity (4)
Define each of the following phenomena:
1. The light bulb
“doesn’t go on”
3. The match
“doesn’t light”
2. “He slipped”
4. The pen
“doesn’t
write”
Time: 10’
2. Defining the Phenomenon to be analyzed.
What’s going on?
1. The light bulb “doesn’t go on”
The phenomenon that produces light
is the heating of the filament when
electrons or electric current flows
through it.
DESCRIPTION OF THE PHENOMENON:
There is insufficient or no flow of electric
current through the filament.
2. Defining the Phenomenon to be analyzed.
What’s going on?
2. “He slipped”
Slipping occurs when the force of
friction is less than the force that
caused him to slide.
F = Impulse that caused
him to slide.
f = Force of friction
DESCRIPTION OF THE PHENOMENON:
F>f
2. Defining the Phenomenon to be analyzed.
What’s going on?
3. The match “won’t light”
In order for a match to light, 3
conditions need to be met:
a) Fuel.- Met with the striking
material and the match head. (OK.)
b) Oxygen.- Provided by the
environment. (OK.)
c) Heat.- Caused by the friction of
the match head against the rough
strip on the matchbox.
DESCRIPTION OF THE PHENOMENON:
There is not enough friction between the match head
and the rough strip on the matchbox to produce the
heat needed for ignition.
2. Defining the Phenomenon to be analyzed.
What’s going on?
4. The pen “doesn’t work.”
In order for the pen to write, ink
needs to flow to the pen’s ballpoint
and over it onto a surface
where it is deposited.
DESCRIPTION OF THE PHENOMENON:
Ink doesn’t flow over the pen’s point.
3. Establishing Cause-Effect Relationship.
First “Why” about the Phenomenon
This question needs to be answered from a
physical and/or logical point of view.
The question needs to be answered for each
element involved in the description made in the
previous step.
At this point, focus on the evidence of the flaws,
that is:
a) Verify the evidence of the causes of the problem in
the field (whether it exists or not, stopping the
analysis for that branch when the cause doesn’t
exist).
b) If it is possible to put a direct countermeasure to
the cause into place, do it and stop the analysis
ensure that procedures or standards are in place to
maintain condition achieved..
3. Establishing Cause-Effect Relationship.
Why does it happen?
Work group activity (4)
Ask the first “Why?” question and answer it for each
phenomenon.
1. The light bulb
“doesn’t go on”
3. The match
“won’t light”
2. “He slipped”
4. The pen
“doesn’t
work”
Time: 15’
3. Establishing Cause-Effect Relationship.
Why does that happen?
1. The light bulb “doesn’t go on”
FIRST WHY:
Why is the flow of electric current
through the filament insufficient
o non-existent?
(The flow of electric current in a flow
of free electrons in the material).
a) There aren’t any free electrons in the material
(The filament material is a dielectric)
b) There’s no energy to move the electrons
c) There is not enough energy
d) There is nowhere for the electrons to flow
(The filament is broken)
Eliminated by
evidence.
3. Establishing Cause-Effect Relationship.
Why does that happen?
2. “He slipped”
FIRST WHY:
F = Impulse that provokes
the slide.
Why is F > f ?
f = Force of friction
OBSERVING “F”:
a) The person is leaning
Eliminated, too much.
b) Some outside force of
nothing
impulse added to F.
pushed
c) The person’s inertia is
him
high.
OBSERVING “f”:
a) The surfaces between his
sole and the floor present little
friction.
b) There is a lubricant between
the surfaces.
3. Establishing Cause-Effect Relationship.
Why does that happen?
3. The match “won’t light”
FIRST WHY:
Why is there not enough friction between the match
head and the matchbox strip to produce the heat
needed to cause ignition?
(In this case of friction, what is
important is that heat be generated)
a) The pressure applied between the match and the
matchbox is too low.
b) The surface of the matchbox is not rough enough.
c) The surface of the match head is not rough enough.
d) There is a lubricant between the surfaces.
e) The friction duration is not long enough to heat the
match head and produce ignition.
3. Establishing Cause-Effect Relationship.
Why does that happen?
4. The pen “doesn’t work.”
FIRST WHY:
Why doesn’t the ink flow over
the pen’s point?
a) Ink isn’t reaching the pen’s point.
b) There’s no pressure on the ink to the
pen’s point. (Gravity, others)
c) There’s nowhere for the ink to flow.
(The ballpoint is blocked.)
d) The ink doesn’t flow over the other
surface.
(Writing “in the air,” or on ice, etc.)
3. Establishing Cause-Effect Relationship.
Steps for developing a
Why - Why Analysis:
. Second “Why”
✻For each answer to the “Why?” in the
previous step, the question “Why?” is
asked again.
✻The answer in this case, and from here on,
should consider the “4 - M’s.”
How to Verify Causes
Use the cause and effect worksheet as
a guide
Go look, listen, feel, ask - “Watch
with a purpose”
Simulate
Make the fix (restore) and monitor
Do the verification on the floor
4. Logical Review of the Analysis
Once you have exhausted your Why-Why Questioning,
do the Cause-Effect Relationships Make Sense and flow
back to the Phenomenon ?
Why? 1
Pulling
Force
Not
Strong
Enough
Why? 2
Seal
between
Suction
Cup and
Carton
inadequate
Vacuum
Force
Not
High
Enough
Phenomenon
Forces
Holding
Carton
too
high
Problem
Missing
Carton
Cartons
Sticking
To Each
Other
Why? 3
Suction
Cup
Wear
Field Check
No Wear
Suction
Cup
Damage
No Damage
Suction
Cup
Inadequate
Material
Could be
Poor
Carton
Surface
Condition
Holding
Fingers
Miss
Adjusted
Holding
Frame
Too
Tight
Why? 4
Dust
on
Carton
Yes
Scratches
on carton
Yes
Surface
Finish
outside
tolerance
Not True
Vacuum
Setting
too low
No
Vacuum
Line
Leaks
No
Suction
Cup
Too Small
Could be
4. Logical Review of the Analysis
“If we solve these causes, (1, 2, ...8)
is it possible that ZERO will be reached (Branch “A”)?”
CAUSE # 1
CAUSE # 2
CAUSE # 3
Branch “A”
CAUSE # 4
CAUSE # 5
CAUSE # 6
CAUSE # 7
CAUSE # 8
4. Logical Review of the Analysis
Repeat the question branch by branch until
the entire analysis has been verified.
BRANCH “A”
BRANCH “B”
BRANCH “C”
BRANCH “D”
Main branch “AA”
BRANCH “E”
BRANCH “F”
BRANCH “G”
BRANCH “H”
5. Checking for Standards and SOP’s
Before taking counter measures, check to see if standards for the
defined counter measure exist.
If not, define the standard. Determing if an SOP is needed.
WHY-WHY
P
r
o
b
l
e
m
Why? F
W
h
y
W W
h h
y y
W
h
y
?
?
?
?
C
R Ci
o aeh
e
ou
s
l
t e c
dk
Std.’
s
E
x
i
s
t
?
A
p
p
l
i
e
d
?
A T SOP
ca E
t k x
i e i
on s
n? t
?
A
c
t
i
o
n
Standards
(4M’s)
h
u
M
a
n
e
q
u
i
p
M
M
e
t
h
o
d
NOK
Y
OK
N
Y
N
Restore
New
Std.
Y
N
X
New
Maint.
Std.
X
X
M
a
t
e
r
i
a
l
Use the 4M’s to
ensure all required
types of standards
exist.
Analysis Steps
1. Understanding the Problem
2. Defining the Phenomenon to be analyzed.
3. Establishing Cause-Effect Relationship
through Why questioning and Field Checks.
4. Logical Review of the Analysis
5. Checking for Standards and SOP’s
Notes and Advice:
The analysis should be done at the problem area,
not in another location that is isolated from the case.
The analysis is a team effort, not by just one person.
The most important thing is the physical and/or
logical description of the phenomenon to be studied.
(Step 1)
The Analysis ends when countermeasures TO
AVOID RECURRENCE of the phenomenon are
found.
Notes and Advice:
■ALWAYS
make a sketch or drawing of the
phenomenon.
■The 4-M’s don’t always apply to every cause to
be analyzed, but we should always consider
them so as not to forget possible “causes of
causes.”
■The more simplicity and objectivity in steps 1
and 2, the easier it is to ensure that all possible
causes are covered.
■Practice develops skill.
■This tool makes us more objective in our way
of looking at things.
Why/Why - NOT!!!
Problem
Why
Why
Why
Why
Why
Action Plan
Already had the answer,
used the tool to “document” it
Brainstorming,
in a room,
no verification
Real WHY-WHY Analysis Example
Problem: Through put of the line 23 is below ideal.
Phenomena: Carton not Picked off the supply stack.
Result: This causes a loss in through put. (Missing Carton)
Missing
Carton
W
h
y
?
1
P
h
e
n
o
m
e
n
o
n
Pulling
Force
Not
Strong
Enough
Forces
Holding
Carton
too
high
Missing
Carton
Why? 1
Why? 2
Pulling
Force
Not
Strong
Enough
P
h
e
n
o
m
e
n
o
n
Forces
Holding
Carton
too
high
Seal
between
Suction
Cup and
Carton
inadequate
Vacuum
Force
Not
High
Enough
Cartons
Sticking
To Each
Other
Holding
Fingers
Miss
Adjusted
Holding
Frame
Too
Tight
Missing
Carton
Why? 1
Why? 2
Pulling
Force
Not
Strong
Enough
P
h
e
n
o
m
e
n
o
n
Forces
Holding
Carton
too
high
Seal
between
Suction
Cup and
Carton
inadequate
Vacuum
Force
Not
High
Enough
Cartons
Sticking
To Each
Other
Holding
Fingers
Miss
Adjusted
Holding
Frame
Too
Tight
Missing
Carton
Why? 3
Suction
Cup
Wear
Suction
Cup
Damage
Suction
Cup
Inadequate
Material
Poor
Carton
Surface
Condition
Loose
Carton
Stack
Flaps
folded
Backward
Vacuum
Setting
too low
Vacuum
Line
Leaks
Suction
Cup
Too Small
Why? 1
Pulling
Force
Not
Strong
Enough
P
h
e
n
o
m
e
n
o
n
Why? 2
Seal
between
Suction
Cup and
Carton
inadequate
Vacuum
Force
Not
High
Enough
Cartons
Sticking
To Each
Other
Forces
Holding
Carton
too
high
Holding
Fingers
Miss
Adjusted
Holding
Frame
Too
Tight
Why? 3
Suction
Cup
Wear
Suction
Cup
Damage
Suction
Cup
Inadequate
Material
Poor
Carton
Surface
Condition
Loose
Carton
Stack
Flaps
folded
Backward
Vacuum
Setting
too low
Vacuum
Line
Leaks
Missing
Carton
Why? 4
Suction
Cup
Too Small
Dust
on
Carton
Scratches
on carton
Surface
Finish
outside
tolerance
Why? 1
Pulling
Force
Not
Strong
Enough
Why? 2
Seal
between
Suction
Cup and
Carton
inadequate
Vacuum
Force
Not
High
Enough
P
h
e
n
o
m
e
n
o
n
Cartons
Sticking
To Each
Other
Forces
Holding
Carton
too
high
Why? 3
Suction
Cup
Wear
Vacuum
Setting
too low
Vacuum
Line
Leaks
Missing
Carton
Not Damaged
Suction
Cup
Inadequate
Material
Poor
Carton
Surface
Condition
Suction
Cup
Too Small
Field Check
Not worn
Suction
Cup
Damage
Holding
Fingers
Miss
Adjusted
Holding
Frame
Too
Tight
Why? 4
Could be
Dust
on
Carton
No Dust
Scratches
on carton
Not true
Surface
Finish
outside
tolerance
Problem
Found to be low
Some Leaks
Correct Size
WHY-WHY
P
r
o W
b h
yy
l
e
m ?
Why? F
W Suction
W
Cup
h Wear
h
y Suction
y
Cup
Damage
Suction
Cup
Inadequate
Material
?
?
C
C
W Ra i h
h o ue
y osle
t e c
dk
?
Dust
on
Carton
Scratches
on carton
Surface
Finish
outside
tolerance
Vacuum
Setting
too low
Vacuum
Line
Leaks
Suction
Cup
Too Small
Std.’sStandards
E
x
i
s
t
?
M
a
t
e
r
i
a
l
A SOP A
A
p
p cT
p E
p t a
l
x
l i k
i
i
i
e
o
e s
e
n
d t
d n?
? ?
?
X
N
N
(4M’s)
h
u
M
a
n
e
q
u
i
p
M
M
e
t
h
o
d
Ntrue
Ntrue
True Y
True Y
True N
NTrue
X
X
X
X
X
X
Train
Train
Y
Y
Y Develop SOP
Develop
Stds
Another example:
General Problem:
Air piston moving too slow
in both directions
Air cylinder
Five Port Valve
Draw the problem
Get an understanding of the process:
Drawing, Parts
Air cylinder
Five Port Valve
Bush
Rod seal
Exhaust
Bottom
seal
Pipes
Adjustable
Restrictor
P0
Get an understanding of the process:
Drawing, Parts, Process
Air cylinder
Five Port Valve
Bush
Rod seal
Exhaust
Bottom
seal
Pipes
Adjustable
Restrictor
P0
Get an understanding of the process:
Drawing, Parts, Process, Forces, Counterforces
Air cylinder
Five Port Valve
Counterforces
Bush
Rod seal
Exhaust
Bottom
seal
Pipes
Forces
Adjustable
Restrictor
P0
Conduct Why/Why
Phenomena
1. Piston slow
moving in Both
directions
1. Why
2. Why
3. Why
4. Why
5. Why
Conduct Why/Why
Defect
1. Why
2. Why
1. 1 Force (pressure)
too low
Field Verification
True
1. Piston slow
moving in both
directions
1. 2 Counterforce
too high
Not True
3. Why
4. Why
5. Why
Conduct Why/Why
Defect
1. Why
2. Why
3. Why
4. Why
1.1.1 pressure p0
too low
True
1.1.2 5 port valve
defect
Not True
1. Piston slow
moving in both
directions
1.1.3 blocked pipe
1.1.4 adjustable
restrictor closed
1.1.5 air leakage
1. 2 Counterforce
too high
Field Verification
1. 1 Force (pressure)
too low
Not True
Not True
Not True
5. Why
Conduct Why/Why
1. Why
3. Why
2. Why
1.1.1 pressure p0
too low
1.1.1.1 not adjusted
after c/o to
shampoo
1.1.2 5 port valve
defect
1.1.3 blocked pipe
1.1.4 adjustable
restrictor closed
1.1.5 air leakage
1. 2 Counterforce
too high
True
1.1.1.2 Air leakage
1. 1 Force (pressure)
too low
1. Piston slow
moving in both
directions
4. Why
Not True
Field Verification
Defect
Conduct Why/Why
1. Why
3. Why
4. Why
1.1.1.1 not adjusted
after c/o to
shampoo
1.1.1.1.1 No Procedure
2. Why
1.1.1 pressure p0
too low
1. 1 Force
(pressure)
too low
1.1.1.2 Air leakage
1.1.2 5 port valve
defect
1. Piston slow
moving in both
directions
1.1.3 blocked pipe
1.1.4 adjustable
restrictor closed
1.1.5 air leakage
1. 2 Counterforce
too high
True
1.1.1.1.2 Lack of
Knowledge
True
Field Verification
Defect
Conduct Why/Why
3. Why
4. Why
1.1.1.1 not adjusted
after c/o to
shampoo
1.1.1.1.1 No Procedure
1.1.1.2 Air leakage
1.1.1.1.2 Lack of
Knowledge
possible Countermeasures
- Develop Procedure
- Retraining, OPL,s etc,
- Visual controls to make easier
to see if off...
Case Study
Why-Why Analysis
Problem Description
Problem Picture
Phenomenon
Problem Statement
What does success look like?
Company A is located on the 30th floor of a
high-rise building. Customers often complain
that elevators are slow in coming, and there is
a fear that it may have an adverse effect on the
company's sales performance.
A study revealed that more visitors come to the
company between 13:00 and 15:00 hours and
that their waiting time averages around 30 sec.
Please solve this problem by appling why-why
analysis
Phenomenon
Why (1)
Why (2)
Why (3)
Why (4)
Have you verified the cause?
Why (5)
Countermeasures
WHY - WHY ANALYSIS
REVIEW VS. OBJECTIVES:
✻ Understand the definition of “Analysis”
✻ Clarify the procedure for developing a Why - Why
Analysis.
✻ Stress the importance of each step of the Why - Why
Analysis.
THE
END
ELIMINATION
OF LOSSES