Download - Eric Coatanea
Searching for design
contradictions and
conflicts with DSM
Method exemplified using a case study of the EU robot competition 2010
Professor Eric Coatanéa
18/06/2010
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System dynamic model
Eurobot 2010
Oranges
Tomatoes
Earns of Corn
H. Ears
of corn
(our)
H. Tomatoes
(our)
Harvesting
Oranges
(Our)
H. Oranges
(Opponent)
H. Tomatoes
(Opponent)
H. Earns of corn
(Opponent)
Dispending
Zone (our)
Dispending
Zone
(opponent)
Dispending
Zone
(opponent)
Technical
knowledge
(Our)Budget
(Our team)
-
-
-
-
-
Opponent
moving
robot
Static
own
robot
moving
robotAvoid
Number of team
members (Our)
Power
required
(W)
+
Remaining
time
Energy used (W)
Detection
time (t)
Software
complexity
(lines)
Available
resources
Beacons
Grey
raised
zone
Fixed
trees
moving
robot
Climb
moving
robotMove
Detection
signal
sent
Detect
Obstacle
or fruit
detected
+
+
+
-+
+
Development time
Match duration (t=90s)
+
-
RefereeTomatoes, corns
and fixed tree
possible locations-
++
Control unit
treatment
power
+
+
+
+
+
Distance
(m)
Number of
acc./dece.
cycles
Speed
required
acceleration
and
-
Weight
collected
-
+
+
Weight
robot
+
Development
time
+
+
Autonomy
-
-
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Construction and Analysis of the System dynamic model
Analysis of the system of interest
It is difficult to analyze the existing interactions and find the loops in
such a graph!
What do we want to do with such type of System Dynamic
model?
1- We would like to clarify what are the design problems that we
should solve in priority?
What is a design problem?
1- A contradiction related to a performance
2- A target that cannot be attained
3- A conflict between performances
Engine + transmission + tank
Cruising Range
Weight
Body
More E&T
permits M
More W constraints CD
Passengers and luggageDevelopment and
manufacturing cost
+-
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Analysis of the system of interest
What are the types of contradictions that we can find in
a system dynamic model?
1- Several factors influencing in an opposite manner a performance
parameter.
Efficient and
developed
educational
systemEducated citizens
Salary level
+
Price level of local
companies
products
+
+
High quality products
+
Plus factor
Minus factor
Selling products+
-Contradicting factors
Performance parameter
Construction and Analysis of the System dynamic model
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Analysis of the system of interest
What are the types of contradictions that we can find in
a system dynamic model?
2- A parameter is influencing in an opposite manner different
performance parameters.
Efficient and
developed
educational
systemEducated citizens
Salary level
+
Price level of local
companies
products
+
+
High quality products
+
Minus factor
Plus factor
Selling products+
-Contradicting factors
Performance parameters
Margin
+
Construction and Analysis of the System dynamic model
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Examples
Contradictions
Some countries would like to
have military planes forces
available far from home country
(possibility to have fast air
support and intervention). This
requires the use of special plane
and boats (expensive).
Contradiction ?
Plus factor: Fast and distant air
support
Minus factor: Cost (requires special expensive
boats and special planes)
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One way to solve partially the contradiction consists of developing
vertical take-off and landing planes
Contradictions
Prototype: Lockheed XFV-1(tail-sitter)
Take-off and landing on the tail
Contradiction ?
Plus factor: Vertical direction of
the fuselage
Minus factor: Visual control and
guidance especially during landing
Examples
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Answer 1 to vertical take-off and landing contradiction
Contradictions
One contradiction solved (Vertical
take-off and landing without need
for runway and visual control and
guidance) but another
contradiction created!
Plus factor: Vertical take-off and
landing without runway and visual
control
Minus factor: Huge energy
consumption during landing and
take-off (limit greatly range of
the planes)
AV-8B Harrier II
New contradiction
Examples
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Answer 2 to vertical take-off and landing contradiction
Contradictions
+
Bell/Agusta
BA609
Examples
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Definition
Contradiction: “Model of a system conflicts that puts incompatible
requirements on functional properties” [M.A. Orloff, Inventive Thinking
through TRIZ]
Contradictions
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Some types of contradictions
- Organizational properties vs. complexity of implementation,
Contradictions
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Some types of contradictions
- Function A vs. Function B (incompatibility of functions)
Contradictions
To provide flame (oxidizer + fuel) To be used under water
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Some types of contradictions
- Technical properties vs. cost,
Contradictions
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Some types of contradictions
- Technical properties vs. complexity of production
Contradictions
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Some types of contradictions
- Technical properties vs. complexity of use,
Contradictions
Autogiro
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Some types of contradictions
Physical property A vs. Physical property B (incompatibility of physical
properties),
Contradictions
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Architectural definition of the
system dynamic model
Analysis of the system of interest Problem formulation
(system location,
environment, goals,
system service functions)
Solution synthesis (architectural
definition of the system dynamic
model)
Solution (system dynamic model
and analysis)
Solution Verification
(verification of the viability of the model via quick
sensitivity analysis)
Confirmation
Verification
and validation planning
Oranges
Speed
required
(m/s)
Budget
(Our team)
Power
required
(W)
Stock
Flow
Converters
Causal link
+
If Speed INCREASE(DECREASE) then
Power INCREASE(DECREASE)
Time
required
(s)
Number
collected
(n)-
H. Oranges
(Our)
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System dynamic model
Analysis of the system of interest
Oranges
Tomatoes
Earns of Corn
H. Ears
of corn
(our)
H. Tomatoes
(our)
Harvesting
Oranges
(Our)
H. Oranges
(Opponent)
H. Tomatoes
(Opponent)
H. Earns of corn
(Opponent)
Dispending
Zone (our)
Dispending
Zone
(opponent)
Dispending
Zone
(opponent)
Technical
knowledge
(Our)Budget
(Our team)
-
-
-
-
-
Opponent
moving
robot
Static
own
robot
moving
robotAvoid
Number of team
members (Our)
Power
required
(W)
+
Remaining
time
Energy used (W)
Detection
time (t)
Software
complexity
(lines)
Available
resources
Beacons
Grey
raised
zone
Fixed
trees
moving
robot
Climb
moving
robotMove
Detection
signal
sent
Detect
Obstacle
or fruit
detected
+
+
+
-+
+
Development time
Match duration (t=90s)
+
-
RefereeTomatoes, corns
and fixed tree
possible locations-
++
Control unit
treatment
power
+
+
+
+
+
Distance
(m)
Number of
acc./dece.
cycles
Speed
required
acceleration
and
-
Weight
collected
-
+
+
Weight
robot
+
Development
time
+
+
Autonomy
-
-
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- Place the variables in a Design Structure Matrix (DSM)
Influence of:
variables
On variables
Analysis of the system of interest
Construction and Analysis of the System dynamic model
A
B
A B
1
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- Let’s consider the following relationships, Can you build the
associated DSM?
40-40C
+5
+2
+3
C
-3-2Is influenced
4
4
Influence (absolute)
0-2B
+10A
BAA
B
C
-2
-4
+1+3
Influence of:
Influence On:
1: Weak influence
2: Average influence
3: Strong influence
4: Very strong influence
Analysis of the system of interest
+2
Construction and Analysis of the System dynamic model
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- If B is a performance variable
A
B
C
-2
-4
+1+3
Influence of:
Influence On:
B is influenced by contradictory
influences, (Visible in column B).
B is providing contradictory
influences to A and C, Visible in
line B).
Analysis of the system of interest
Construction and Analysis of the system dynamic model: Contradictions of
type 1 and 2
+2
40-40C
+5
+2
+3
C
-3-2Is influenced
4
4
Influence (absolute)
0-2B
+10A
BA
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- Indirect influences and loops: raise the power of the matrix
0-40C
+2
+3
C
0-2B
+10A
BA
0-40C
+2
+3
C
0-2B
+10A
BA
-80+8C
-6
+2
C
-100B
-12-2A
BA
Analysis of the system of interest
Construction and Analysis of the system dynamic model
A
B
C
-2
-4
+1+3
+2
What is the meaning of the value -10
in column B, line B?
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- By continuing raising the power of the matrix, the most influential
variables are determined but also the most influenced variables
Analysis of the system of interest
Construction and Analysis of the system dynamic model
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- Finding the conflicting loops require in this case to raise the matrix
below to power 4.
A
B
C
-2
-4
+1+3 Influence
of:
Influence On:
Analysis of the system of interest Construction and Analysis of the system dynamic model: Conflicts of type 1
and 2
-2
Cl.
2
Cl.
1
Cluster 2Cluster 1
0-200-20D
+30+1000E
00-4000F
0
-2
0
D
0
0
0
E
0
0
0
F
0-40C
0
+3
C
Is influenced
Influence (absolute)
0-2B
+10A
BA
D
Cluster 1
Cluster 2
E
F
-2
-4
+1+3
-2
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Analysis of the system of interest
Oranges
Tomatoes
Earns of Corn
H. Ears
of corn
(our)
H. Tomatoes
(our)
Harvesting
Oranges
(Our)
H. Oranges
(Opponent)
H. Tomatoes
(Opponent)
H. Earns of corn
(Opponent)
Dispending
Zone (our)
Dispending
Zone
(opponent)
Dispending
Zone
(opponent)
-
Static
own
robot
moving
robotAvoid
moving
robot
Climb
moving
robotMove
Remaining
time Detection
time (t)
Detection
signal
sent
Detect Obstacle
or fruit
detected+
+
+
Weight
collected
(B) Tomato
harvesting
Construction and Analysis of the system dynamic model: Conflicts of type 1
and 2
It is important to give names to loops
in order to see if they have a real
importance on the system
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From Anticipation to Action: A handbook of Strategic prospective, Michel Godet, Dunod Editor, 1991.
System Thinking: Managing Chaos and Complexity: A platform for Designing Business Architecture, J.
Gharajedaghi, Elsevier B.H., 2006.
Business Dynamics-Systems Thinking and modeling for a complex world, John D. Sterman, Irwin- Mc graw-
Hill Editor, 2000.
Ingéniérie et intégration des systèmes, J.P. Ménadier, Hermès editor, 1998.
Inventive Thinking through TRIZ, M.A. Orloff, 2nd Edition, 2006.
Engineering of creativity: Introduction to TRIZ Methodology of Inventive Problem Solving, S.D. Savransky,
CRC Press, 2000.
Main References for part 1
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Thank you
Questions?