Systems Theory and Modelling
© David O’Sullivan, NUI Galway
Seminars
IntroductionDefining Innovation Innovation ProcessUnderstanding GoalsDefining ObjectivesManaging IndicatorsSystems Theory and ModellingCreativity and Idea GenerationManaging Project PortfoliosLeading Innovation TeamsManaging Results and Knowledge
© David O’Sullivan, NUI Galway
This Lecture
• Open Systems• General Systems Theory (GST)• GST Traits• System Classification• Systems Analysis and Modelling• Activity Modelling (IDEFo)
© David O’Sullivan, NUI Galway
Reduction vs. Systems
• 1950’s the main approach to understanding was ‘reductionism’ – divide something into its parts
• Ludwig von Bertalnffy proposed systems thinking – discover how something interacts with its environment
© David O’Sullivan, NUI Galway
Open Systems
• All living and many non-living things are open systems
• Systems theory gives us a way to ‘think about’ open systems
• Systems theory lays the foundation for the analysis and modelling of systems
• Systems theory provides an analytical framework for comprehending dynamic interrelated operating systems
© David O’Sullivan, NUI Galway
Open System
Sense Response
ENVIRONMENT
OPENSYSTEM
© David O’Sullivan, NUI Galway
University – Open System
UNIVERSITY
Policy
Approved Funding
Industry Needs
Students
Funding Requests
New Knowledge
Graduates
© David O’Sullivan, NUI Galway
Systems Thinking
• holistic approach to problem solving
• reflecting on how the organisation relates to its business environment and
• how factors in the environment can affect the organisation
© David O’Sullivan, NUI Galway
Definition of ‘System’
“... an identifiable, complex dynamic entity composed of discernibly different parts or subsystems that are interrelated to and interdependent on each other and the whole entity with an overall capability to maintain stability and to adapt behaviour in response to external influences” [Webster’s]
© David O’Sullivan, NUI Galway
General Systems Theory
• Science of understanding open systems theory
• GST provides a framework to study open systems
• GST is not too general nor too specific
© David O’Sullivan, NUI Galway
Boulding’s Explanation
“Somewhere … between the specific that has no meaning and the general that has no content there must be, for each purpose and at each level of abstraction, an optimum degree of generality”
© David O’Sullivan, NUI Galway
Beckett’s explanation
"The trust of general systems .. is to draw attention to the study of relationships of parts to one another within the wholes”
© David O’Sullivan, NUI Galway
GST Traits
• Systems …– are Goal Seeking– are Holistic– have Hierarchy– have Inputs and Outputs– transform inputs into outputs– consume and/or create Energy– are affected by Entropy– have Equifinality– have Feedback
© David O’Sullivan, NUI Galway
Goal Seeking All open systems must have goals There are two types
Inner directed goals Outer directed goals
Design strategies are typically “outer directed” goals
Maintenance strategies are an “inner directed” goal
© David O’Sullivan, NUI Galway
Holistic SUB SYSTEM
SUB SYSTEM
SUB SYSTEM
SUB SYSTEM SUB
SYSTEM
SUB SYSTEM
SUB SYSTEM
Boundry
• Fredrick Hagel (1770-1831)– The whole is more than the sum of the parts– The whole determines the sum of the parts– The parts cannot be understood if considered
in isolation from the whole– The parts are dynamically interrelated and
interdependent
© David O’Sullivan, NUI Galway
Hierarchical
WHOLE SYSTEM
SUB SYSTEM
SUB SYSTEM
SUB SYSTEM
SUB SYSTEM
SUB SYSTEM
SUB SYSTEM
SYSTEMS
MORE GENERAL
MORE DETAIL
PLANT LEVEL
DEPARTMENT LEVEL
CELL LEVEL
PROCESS LEVEL
WORKSTATION LEVEL
© David O’Sullivan, NUI Galway
Transform Inputs into Outputs
TRANSFORM INPUTS TO OUTPUTS
TRANSFORM INPUTS TO OUTPUTS
ERROR FEEDBACK
STATUS FEEDBACK
OUTPUT
INPUT
INPUT
OUTPUT
INPUTOUTPUT
INPUT
© David O’Sullivan, NUI Galway
Entropy
• A measure of the amount of disorder in a system
• Everything disintegrates over time• Negative entropy or centropy• Effects of entropy are offset by the
system transforming itself continuously• Maintain order through such things as
repairs, maintenance and possibly growing by importing ‘energy’
© David O’Sullivan, NUI Galway
Energy, Equifinality and Feedback
• Systems create/consume energy– Physical– Emotional
• Equifinality is the ability for systems to achieve goals in a number of ways
• This flexibility allows systems avoid the effects of entropy
• Systems have feedback - feedback can allow a system to change its direction
© David O’Sullivan, NUI Galway
System Classification• Checkland's classification
– Natural Systems (ecological systems, human beings)– Physically Designed Systems (bridges, machines)– Abstract Design Systems (Languages, Mathematics)– Human Activity Systems (Politics, Banking)– Transcendental Systems (Beyond knowledge or
comprehension)• Boulding’s Classification
Transcendental
Social Oganisation
Human
Animal
Genetic-societal
Open System
Cybernetics
Clockworks
Frameworks1
2
3
4
5
6
7
8
9
© David O’Sullivan, NUI Galway
Boulding’s Classification• Frameworks
– static structures (e.g. camshaft, skeleton, formal company organisations, rock)
• Clockworks– timing mechanisms (e.g. self winding clocks)
• Cybernetics– elementary closed systems with feedback (e.g. thermostats)
• Open system– elementary forms of life interact with their environment in order to change their
behaviour
• Genetic-societal systems– exchange information with other subsystems
• Animal system– mobility, self-awareness, and goal orientation-highly complex
• Human system– intelligence gives the human system the ability to think about the future, its goals,
and how to reach them.
• Social organisation – organisations which have their own combined goals, needs
• Transcendental, – all other systems not yet comprehended
© David O’Sullivan, NUI Galway
Conclusions
• Views of GST are universal • GST combats ‘isolationist’ tendencies among
engineers, systems analysts, business analysts, IT specialists, etc. etc.
• GST offers a framework for understanding all systems
• Benefits of GST to design of systems are significant
• Theory of GST lays at the foundation of much new thinking in - including ‘Learning Organisations’, ‘Structured Analysis’, ‘Sociotechnical Design’ and ‘Strategic Planning’
© David O’Sullivan, NUI Galway
5 minute break!
• Open Systems• General Systems Theory (GST)• GST Traits• System Classification
• Systems Analysis and Modelling• Activity Modelling (IDEFo)
Systems Analysis and Modelling
© David O’Sullivan, NUI Galway
Modelling
• Represent existing and future systems
• Models are in-complete • Various models represent different
perspectives and levels of abstraction• Modelling techniques should be selected
to enhance communications between designers and users
© David O’Sullivan, NUI Galway
Perspectives
Managing Director
ManufacturingEngineer
SoftwareEngineerSupervisor
ManufacturingManager
Accountant
© David O’Sullivan, NUI Galway
Techniques
© David O’Sullivan, NUI Galway
IDEFo
• Background• Activity Modelling• Cell Modelling• Hierarchical Decomposition• Principles of IDEFo• IDEFo Approach
© David O’Sullivan, NUI Galway
Background
• IDEFo is an activity or process modelling technique
• Developed through US AirForce R&D• Basic idea: Adopt a common language for all
designers• Original ideas by Ross and his SADT technique• Sister languages
– IDEF1x used for data structure modelling– IDEF2 used for dynamic modelling (simulation)– Etc.
• http://www.idef.com
© David O’Sullivan, NUI Galway
Cell Modelling
© David O’Sullivan, NUI Galway
Cell Modelling
© David O’Sullivan, NUI Galway
Cell Modelling
© David O’Sullivan, NUI Galway
Hierarchical Decomposition
© David O’Sullivan, NUI Galway
Arrows
© David O’Sullivan, NUI Galway
ICOM Codes
© David O’Sullivan, NUI Galway
Boundary Arrow Correspondence
© David O’Sullivan, NUI Galway
Tunnelled Arrows
© David O’Sullivan, NUI Galway
Modelling Demonstration
• Choose an activity!• Choose purpose and viewpoint!• Creating the A-0 diagram• Creating the A0 diagram• Creating the A-1 diagram
© David O’Sullivan, NUI Galway
Node Index and Tree
• A0 Manufacture Product– A1 Plan For Manufacture
• A11 Identify Manufacturing Methods• A12 Estimate Requirements, Time, Cost to• A13 Develop Production Plans• A14 Develop Support Activities Plan
– A2 Make and Administer Schedules and Budgets• A21 Develop Master Schedule• A22 Develop Coordinating Schedule• A23 Estimate Costs & Make Budgets• A24 Monitor Performance To Schedule & Budget
– A3 Plan Production
© David O’Sullivan, NUI Galway
Principles of IDEFo
• Cell Modelling Graphic Representation– Boxes-and-arrows show graphically all activities in a
system• Conciseness
– Two dimensional ‘structured’ diagrams and text provide concise detail
• Communication– Simple boxes and arrows, limitation of detail, structured
presentation of information• Rigor and Precision• Methodology
– Step-by-step approach• Organisation versus Function
– Separation of organisation from function
© David O’Sullivan, NUI Galway
Rigor and Precision
• Detail exposition control (no more than six boxes)• Limited context (no omissions or unnecessary detail)• Diagram interface inter-connectivity• Data structure connectivity (through parenthesis)• Uniqueness of labels and titles• Syntax rules for graphics• Inputs are separate from controls• Data arrow labelling requirements• Minimum control of function• Purpose and viewpoint
© David O’Sullivan, NUI Galway
IDEFo Methodology
• Select a viewpoint and purpose• Limit the subject matter• Create a top level diagram (A-0, one box only)• Create a context diagram (A-1, if necessary)• Create AO diagram (A0, two to six boxes)• Create subsequent diagrams, text and glossary• Review material and check for purpose and viewpoint• Additional pointers
– Avoid trivial activities and flows– Limit necessary detail at each level– Group related arrows and activities to simplify detail– Be clear, precise and consistent– Think control and not flow– Delay the addition of detail– If in doubt incoming flows should be controls– Annotate as you develop each diagram
© David O’Sullivan, NUI Galway
Sample
• See course notes on 'Enterprise Modelling'
© David O’Sullivan, NUI Galway
Summary
• Open Systems• General Systems Theory (GST)• GST Traits• System Classification• Systems Analysis and Modelling• Activity Modelling (IDEFo)
© David O’Sullivan, NUI Galway
Online Assignment
• Develop an IDEFo model for your organisation
• Produce A-0, A0, and A-1 diagrams– Graphics plus Description Text
• Upload model into ‘Models’ web part
Top Related