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Optimizing complex systems represents a challenge. Traditional approaches to complex systems development either ignore the issue or optimize subsystems. Some approaches might even iterate through a number of architectures to identify the best one. This paper investigates an alternative approach, namely architecting the complex system to optimize the interactions between the subsystems at design time. The paper uses the interactions in the sex life of males and females (the system) as a case study and shows that better (more pleasurable) results can be achieved by optimizing the system for the interaction at the interface than for the individual (subsystem) experience. The paper then provides diverse examples where systems were or could have been optimized for interactions if seen from the holistic perspective. These instances include weapons systems, logistics systems, the Apollo program, the human cardiovascular system, an online classroom, the INCOSE Australia chapter and a library. The paper concludes with recommendations for further research
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March 2011 1.21 /Applying holistic thinking11
The Sixth National ConferenceINCOSE_IL 2011
• חשיבה מערכתית ומידול מערכתי• Applying holistic thinking to
improving your sex life• Dr Joseph Kasser
• National University of Singapore
March 2011 1.21 /Applying holistic thinking2
Topics• Systems approach to solving problems• The common vision of the solution
– CONOPS• Aggregating functions• Complexity and its reduction• Optimizing your sex life• Optimizing systems for interactions• Examples• Generic model
March 2011 1.21 /Applying holistic thinking3
Systems approach to problemformulation
Observe
Formulatehypothesis
Testhypothesis
Research
Refuted Supported
March 2011 1.21 /Applying holistic thinking4
Systems approach to CONOPSformulation
FormulateCONOPS (9)
CONOPSComplete?
Research
No
Yes
March 2011 1.21 /Applying holistic thinking5
Example: CONOPS of a system
A
E
B
F
C
G
D
H
March 2011 1.21 /Applying holistic thinking6
N2 chart representationA B C D E F G
A
B
C
D
E
F
G
outputs – horizontal squares
inputs–
vertical squares
March 2011 1.21 /Applying holistic thinking7
N2 chart representationA
B
C
D
E
F
G
Houtputs – horizontal squares
inputs–
vertical squares
March 2011 1.21 /Applying holistic thinking8
N2 chart representationA o o o o
o B o o o o
o C o o o
o o o D o o
o o E o o
o o o F o o
o o o o G o
o o o o H
Output
Input
March 2011 1.21 /Applying holistic thinking9
N2 chart representationA o o o o
o B o o o o
o C o o o
o o o D o o
o o E o o
o o o F o o
o o o o G o
o o o o H
March 2011 1.21 /Applying holistic thinking10
Aggregated (synthesized) subsystems
A o o
o BCD o o
o o EFG
o o H
A
BCD EFG
H
Subsystems withinsubsystem
March 2011 1.21 /Applying holistic thinking11
Alternative subsystem grouping-1
A o o o o
o B o o o o
o C o o o
o o o D o o
o o E o o
o o o F o o
o o o o G o
o o o o H
March 2011 1.21 /Applying holistic thinking12
Alternative subsystem grouping-2A o o o o
o B o o o o
o C o o o
o o o D o o
o o E o o
o o o F o o
o o o o G o
o o o o H
March 2011 1.21 /Applying holistic thinking13
Alternative subsystem grouping-3A o o o o
o B o o o o
o C o o o
o o o D o o
o o E o o
o o o F o o
o o o o G o
o o o o H
March 2011 1.21 /Applying holistic thinking14
Alternative subsystem grouping-4A o o o o
o B o o o o
o C o o o
o o o D o o
o o E o o
o o o F o o
o o o o G o
o o o o H
March 2011 1.21 /Applying holistic thinking15
Alternative subsystem grouping-5A o o o o
o B o o o o
o C o o o
o o o D o o
o o E o o
o o o F o o
o o o o G o
o o o o H
March 2011 1.21 /Applying holistic thinking16
Which aggregation option tochoose?
• How to make choice?• Literature suggests
– Minimum coupling– Maximum cohesion
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Types of coupling-1• Content coupling (high): one module modifies or relies
on the internal workings of another module– e.g. accessing local data of another module
• Common coupling: two modules share the same globaldata– e.g. a global variable
• External coupling: two modules share an externallyimposed data format, communication protocol, or deviceinterface.
• Control coupling : one module controls the logic ofanother, by passing it information on what to do– e.g. passing a what-to-do flag
March 2011 1.21 /Applying holistic thinking18
Types of coupling-2• Stamp coupling (Data-structured coupling): modules
share a composite data structure and use only a part ofit, possibly a different part– e.g. passing a whole record to a function which only needs one field
• Data coupling: modules share data through, forexample, parameters.
• Message coupling (low) : Modules are not dependenton each other, instead they use a public interface toexchange parameter-less messages.
• No coupling: modules do not communicate at all withone another.
March 2011 1.21 /Applying holistic thinking19
Types of cohesion*
• 1. Coincidental: elements have no relationship• 2. Logical: elements performing similar functions• 3. Temporal: elements that are activated at a single time• 4. Procedural: elements make up a single control
sequence.• 5. Communicational: elements that operate on the
same input data or produce the same output data.• 6. Sequential: The output from one element in the
component serves as input for some other element.• 7. Functional: Each element is necessary for the
execution of a single higher level function.
*Ian Sommervile 1998
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Factors for Complexity*
• A large number ofmembers or subsystems– size, scale
• Strong interactionsbetween the subsystems
• Combination of the above
* Allison, 2004
March 2011 1.21 /Applying holistic thinking21
Reducing complexity
• Weaken interactions between subsystems– Minimize coupling
• Use a small number of subsystems at anylevel in the hierarchy– Maximize cohesion
• Configure subsystems for the maximumdegree of homeostasis
March 2011 1.21 /Applying holistic thinking22
Approaches to the optimizationproblem
• Subsystem-centric approaches– (min) coupling and (max) cohesion
• System-centric approach– Maximum functional cohesion– Message coupling desirable– Small number of subsystems– Homeostatic subsystems
• At HKMF Layer 2+
March 2011 1.21 /Applying holistic thinking23
Systems vs. Holistic• Systems engineering
– An activity that deals with parts and their interactions as a whole(Kasser and Hitchins, 2009)
• Systems approach– An approach to problem solving that views any problem as a part of a
bigger system, and in developing a solution, sees that solution beingachieved through the interaction of system elements*, such that theproperties of the whole are beyond the properties of the individual parts(Halligan, 2010).
• Holistic approach– an approach that optimises the system for the interactions between
the subsystems* at design time, rather than an approach thatoptimizes the subsystems after the subsystem boundaries have beendetermined. *Bold text by this author.
March 2011 1.21 /Applying holistic thinking24
Improving your sex life
• System (of systems?) problem• Definition of problem - issues• Subsystem optimization
– Male experience– Female experience
• System optimization– Mutual experience
• Quality or quantity?– Define ‘quality’ and ‘quantity’
March 2011 1.21 /Applying holistic thinking25
System optimization alternatives• Optimize subsystem
– (male) experience• Optimize system
– (mutual) experience– Approach chosen
March 2011 1.21 /Applying holistic thinking26
Research issue• Standard Type V holistic thinking approach• Research the issues• Generic thinking
– Literature review of domain– Access lessons learned by others
• Neglected but critical step in current process
• Gain an understanding of the situation– Do some prototyping
• Interface issues• Cause and effect
– Time delays
• Feedback– Negative and positive
March 2011 1.21 /Applying holistic thinking27
The system• Environment• Interactions via multiple
interfaces• Mental
– Verbal– Behavioral
• Consideration• Respect
• Physical– Tactile
• Other
March 2011 1.21 /Applying holistic thinking28
ResultsBragging again
March 2011 1.21 /Applying holistic thinking29
Complex system optimizationproblem
• How do you optimize a complex system?• Subsystem
– less than optimal• Interactions
– We do so, but sometimes don’t think of it inthat way
– Needs further research
March 2011 1.21 /Applying holistic thinking30
Examples• Weapons systems• The Royal Air Force (RAF) Battle of Britain Air Defence
System (RAFBADS)• Logistics systems• The Apollo Program• The MIR space station• The human cardiovascular system• A distance learning classroom• The Library• Forming the International Council on Systems
Engineering (INCOSE) Australia chapter
March 2011 1.21 /Applying holistic thinking31
Generic model• The N2 chart is only a start• The number of subsystems is small, if the interface
between the major subsystems is complicated enough itcan be considered as a subsystem– This facilitates understanding of the system
• The cohesion of each subsystem is maximized– The subsystems are designed for homeostasis
• The coupling is minimized• The system is optimized for interaction at the interfaces
– Interaction is interface dependent
• Requires thinking, tools do not yet exist
March 2011 1.21 /Applying holistic thinking32
Summary• Systems approach to solving problems• The common vision of the solution
– CONOPS• Aggregating functions• Complexity and its reduction• Optimizing your sex life• Optimizing systems for interactions• Examples• Generic model
March 2011 1.21 /Applying holistic thinking33
Questions and comments
