Lab #2: Problem-Solving and
Improvement
MG/IE 3400 – Production System Design
7-Step Process
1
2
THEME
DATA
3
4
5
6
ROOT CAUSE
SOLUTION
CONFIRM
RESULTS
7
STANDARDIZE
REFLECT
Yes
No
STEP OBJECTIVE
•
Describe the Problem
•
Get the Facts
•
Brainstorm
• One complete sentence
• Collect your own data
• Ask why 5 times
• Customer focused
• Go to the site
• Involve experts
• Supports
company/dept. goals
• Seek multiple variables
• Plan Solution to
Address Root Cause
• Did Experiment Work?
• Run experiment
• Construct comparative
Paretos for all levels
analyzed in Step 2
• Establish schedule for
key actions
• Document the process
• Appropriate level
• Stratify/cut data in many
ways
• Assess positive and
negative side effects
• Measurable
•Look for the “Fat Rabbit”
• Show run chart over
time with milestones
noted
• Provide problem
overview/magnitude
• Identify Strengths/Weaknesses
of the 7-Step Process Used
• Summarize lessons learned
• Train people involved
• Confirm results with the
customer and those who
use the process
• Involve affected
individuals
• Construct Paretos
• Weakness oriented
• Standardize The New Process
Across all Like Processes
• Summarize achievements
• Monitor the results
• Identify next spin/project
• Communicate the new
standard
• Show schedule for spin
• How can the team be sure
the fix will stick?
• Maintain the gain.
STANDARD TOOLS
Checksheet
¦ High Level Flow Chart
Inputs
Ishakawa Diagram
(a.k.a. Fishbone or
Cause & Effect)
1
2
3
4
5
6
7
What
When
Where
How
24
100% 24
20
80%
16
60%
12
Pareto Charts
¦ Run Chart
4 W's & 1H Chart
Who
Process Outputs
24
100%
20
80%
16
Why
is "Fat
Rabbit"
Happening?
20
16
Who What When Where How
Weaknesses
¦
150%
120%
100%
12
40%
8
Time Line of Experiment
60%
Strengths
4 W's & 1H & 1C = Check
Before and After Pareto
8
70%
4
20%
4
40%
0
0%
0
0%
Countermeasures
*
*
*
Old Flow Chart
vs. New Flow Chart
Positive/Negative
Side Effects
Next Problem
Selection
12
40%
4
20%
0
0%
Run Chart
Detail Flow Chart
of Process
Run Chart (Monitor)
Item
Weakness
8
Gantt Chart
Solution Implemented
Time
Time
No fat rabbit:
inconclusive
Time
1
2
3
4
5
6
7
Plan
v.
Actual
FOLLOW THE LOGIC CHAIN
7-Step Process Flowchart
TimeWise Improvement
THEME
DATA
ROOT CAUSE
Plan
SOLUTION
Do
Today
CONFIRM
RESULTS
Check
Next Week
Two Weeks
STANDARDIZE
Yes
Act
REFLECT
1. Theme Selection
Identify the problem team will address


prioritize to identify the most important problem
address one of five ‘evils’: defects, delays, mistakes, waste,
and accidents
A good theme is:




measurable
customer-focused
action-oriented, focused in weakness
does not state causes or solutions
2. Data Collection and Analysis
Investigate the problem from different
viewpoints, establish benchmarks
What factors influence the problem?



Checksheets for data collection
Fishbone diagram
Pareto diagram
Data from TimeWise
Morning
session 1
session 2
session 3
Average Cycle Time (min)
9 (others > 15)
all > 15
all > 15
# Units in Ending WIP
10 Blue, 10 Black 28 Blue, 60 Black 40 Blue, 42 Black
# Units on Time
0
6
5
# Units Shipped Late
3
0
5
# Units in Finished Goods Warehouse 4 Blue, 1 Black
0
5 Blue, 0 Black
# Failed
3 lots
3 lots
3 lots
# Passed
1 lot
1 lot
1 lot
# Orders Outstanding
42
24 Black, 15 Blue
35
# Orders Waiting at Kitting
10
3
1.5
Average Cycle Time (min)
# Units in Ending WIP
# Units on Time
# Units Shipped Late
# Units in Finished Goods Warehouse
# Failed
# Passed
# Orders Outstanding
# Orders Waiting at Kitting
Afternoon
session 1
session 2
session 3
greater than shift greater than shift
11:30, 14:20
38 black, 22 blue 56 black, 28 blue 18 black, 16 blue
7 (3 orders)
8 (4 orders)
11 (5 orders)
0
4 (3 orders)
16 (9 orders)
0
0
3
2
3
1
0
1
4
43 (40bk, 30bl)
38 (38bk, 29bl)
29
6
4
6.5
TimeWise: Quality Problems
18
16
14
12
10
8
6
4
2
0
Quadrant
Marker
Colors
Parallelism Ornamental Quadrant
- Face and
Plate
Marker
Movement Location Alignment
Functional Hand Color
Test
3. Causal Analysis
Talk to people closest to the work to discover the
‘real’ problem
Fishbone diagrams to explore causes more deeply
(‘drill down’ to greater levels of detail)
Why, why, why, why, why … until you have a root
cause, based on data
4. Solution Planning
What solutions exist that prevent the
recurrence of the root cause?


Advantages
Disadvantages, impact on other processes
Run experiments
How will results be measured?
Process Analysis
Calculate coefficient of variation for
each major step in the process
CV = std dev/mean
Low variability: CV <0.75
Moderate variability: 0.75 < CV <1.33
High variablity: CV >1.33
Process Analysis, cont…
What is capacity? Capacity is determined by the
bottleneck operation(s). How can you estimate it?
Calculate TAKT Time
Analyze assembly operations



What are sub-elements?
Are they necessary?
How long do they take?
Example
Task
Time
(Sec)
Precedence
A
B
C
D
E
F
G
H
I
J
K
40
55
75
40
30
35
45
70
15
65
40
None
None
None
A
A,B
B
D,E
F
G,H
I
C,J
510
Number of
Following
Tasks
Positional
Weight
4
4
4
3
3
2
1
0
205
195
225
165
190
120
105
40
Total Task Time
Desired production rate = 200/day. Assume 8 hours/day
Positional Weights
Station
Task
Time
Time
so Far
Ready
Tasks
Balance Delay D
D = [k* C -
ti ] / k* C
where
C = cycle time
k*= number of stations
ti = time for task i