in d ealing with complexity ENGN2219/COMP6719 2020 - PowerPoint PPT Presentation

The Role of Simulation in d ealing with complexity ENGN2219/COMP6719 – 2020 Shayne.Flint@anu.edu.au Research School of Computer Science College of Engineering and Computer Science

Agenda … • Thinking about complexity – Dave Snowden’s Cynefin Framework • Dealing with complexity – System Dynamics – Boyd’s OODA loop • The role of simulation – Brooks’ Law example 2

Thinking About Complexity… 3

Thinking about complexity … • The Cynefin sense-making framework – Pronounced “KUN-iv-in” (It’s a Welsh word!) – Created in 1999 by Dave Snowden – http://cognitive-edge.com • We require different kinds of thinking for – Simple Problems – Complicated Problems – Complex Problems – Chaotic Problems 4

The Cynefin Sense-making Framework Unpredictable Predictable 5

The Cynefin Sense-making Framework Complicated Predictable Unpredictable Simple 6

The Cynefin Sense-making Framework Complex Complicated Unpredictable Predictable Chaotic Simple 7

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Dealing with Complexity 12

Dealing with complexity • Experimentation is at the core – Probe – with safe to run experiments – Sense – what works & what doesn’t – Respond – with emergent practices • System Dynamics modeling and simulation can help • We will also look at why Agility is important when dealing with complexity 14

System Dynamics • An approach to understanding the behavior of complex systems over time – Developed by Jay Forrester at MIT in the 1950’s – Originally focussed on industrial processes – Now widely used for policy analysis and design • Systems are represented using – Causal Loop Diagrams (CLD) – Stock and Flow Diagrams (SFD) 15

CLD Example – using Exit Mould 16

CLD Example – using Exit Mould SYMPTOM SYMPTOM Mould on my bathroom tiles 17

CLD Example – using Exit Mould + SYMPTOM FIX SYMPTOM FIX Mould on my Apply Exit Mould bathroom tiles and wipe down tiles 18

CLD Example – using Exit Mould + SYMPTOM FIX SYMPTOM FIX Mould on my Apply Exit Mould bathroom tiles and wipe down tiles - 19

CLD Example – using Exit Mould + SYMPTOM FIX delay SYMPTOM FIX Mould on my Apply Exit Mould bathroom tiles and wipe down tiles - UNEXPECTED CONSEQUENCE UNEXPECTED CONSEQUENCE + 20

CLD Example – using Exit Mould + SYMPTOM FIX SYMPTOM FIX Mould on my Apply Exit Mould bathroom tiles and wipe down tiles - UNEXPECTED CONSEQUENCE UNEXPECTED CONSEQUENCE + Exit Mould damages grout and tile surface 21

CLD Example – using Exit Mould + SYMPTOM FIX SYMPTOM FIX Mould on my Apply Exit Mould bathroom tiles and wipe down tiles - PROBLEM UNEXPECTED CONSEQUENCE PROBLEM UNEXPECTED CONSEQUENCE + Damage encourages Exit Mould damages growth of deep mould grout and tile surface + 22

CLD Example – using Exit Mould + SYMPTOM FIX SYMPTOM FIX + Mould on my Apply Exit Mould bathroom tiles and wipe down tiles - PROBLEM UNEXPECTED CONSEQUENCE PROBLEM UNEXPECTED CONSEQUENCE + Damage encourages Exit Mould damages growth of deep mould grout and tile surface + 23

“Fixes That Fail” This is an example of a System Archetype (a common pattern of behaviour) 24

Other Fixes that Fail … • The war on terror • Building freeways • Borrowing money to pay interest • Cutting maintenance and repair costs 25

Dealing with a staff shortage … SYMPTOM SYMPTOM Staff Shortage (cannot employ new people) 26

Dealing with a staff shortage … + SYMPTOM FIX SYMPTOM FIX Staff Shortage (cannot employ new people) 27

Dealing with a staff shortage … + SYMPTOM FIX SYMPTOM FIX Staff Shortage Increase overtime (cannot employ new people) 28

Dealing with a staff shortage … + SYMPTOM FIX SYMPTOM FIX Staff Shortage Increase overtime (cannot employ new people) - 29

Dealing with a staff shortage … + SYMPTOM FIX SYMPTOM FIX Staff Shortage Increase overtime (cannot employ new people) - UNEXPECTED CONSEQUENCE UNEXPECTED CONSEQUENCE + 30

Dealing with a staff shortage … + SYMPTOM FIX SYMPTOM FIX Staff Shortage Increase overtime (cannot employ new people) - UNEXPECTED CONSEQUENCE UNEXPECTED CONSEQUENCE + Physical and mental health issues 31

Dealing with a staff shortage … + SYMPTOM FIX SYMPTOM FIX Staff Shortage Increase overtime (cannot employ new people) - PROBLEM UNEXPECTED CONSEQUENCE PROBLEM UNEXPECTED CONSEQUENCE + Physical and mental health issues + 32

Dealing with a staff shortage … + SYMPTOM FIX SYMPTOM FIX + Staff Shortage Increase overtime (cannot employ new people) - PROBLEM UNEXPECTED CONSEQUENCE PROBLEM UNEXPECTED CONSEQUENCE + Increased sick leave Physical and mental health issues + 33

There are many such archetypes … • System Archetypes describe patterns of behavior that surface in many different domains • They help us – think about the possible behavior of complex systems – understand why a complex system behaves the way it does, and – identify things we can do to change that behavior (ie. the things that work and don’t work). 34

The need for agility 35

John Boyd • Fighter pilot • Military, sport and business strategist 36

Boyd’s OODA Loop • A continuous process of learning and change in competitive environments 37

Speed is the key to success • Success comes from getting around your OODA loop more quickly than your competitor – Business, Nature, Sport, Politics … • If your competitor is quicker than you: – Your competitor's behavior will eventually appear chaotic – you will be confused – You will make bad decisions - based on ‘ Orientation ’ and ‘ Observations ’ that are no longer valid – You will lose or fail • Complex systems often evolve rapidly – You need to experiment, learn and act quickly 38

The role of simulation 39

How can simulation help • We can simulate the behavior of complex systems – eg. System Dynamics Stock & Flow models • We can do this quickly – In order to get through our OODA loop quickly • We can run many simulations based on different parameters – That is, we can run a series of different ‘experiments’ – To find out what works & what doesn’t 40

SFD Simulation Example - Brooks’ Law • Fred Brooks – Turing Award 1999 – Author of “ The Mythical Man-Month ” – Author of “ No Silver Bullet ” 41

SFD Simulation Example - Brooks’ Law “Adding manpower to a late software project makes it later. ” Brooks’ Law ● Note that in his book ‘ The Mythical Man-Month’ , Brooks says that this law is an ‘ outrageous oversimplification’. ● In reality, adding people to a project is a complex problem ● We can explore this problem using System Dynamics and Simulation. 42

SFD Simulation Example - Brooks’ Law https://insightmaker.com/insight/4648/Clone-of-Brooks-Law 43

Live Demonstration

SFD Simulation Example - Brooks’ Law • No new developers at day 100 45

SFD Simulation Example - Brooks’ Law • 5 new developers at day 100 46

SFD Simulation Example - Brooks’ Law • 15 new developers at day 100 47

SFD Simulation Example - Brooks’ Law • 15 new developers at day 100, decreased communications 48

SFD Simulation Example - Brooks’ Law • But, how do we reduce communication? – Fewer meetings? – Restrictions on email use? – ... • … and what are the consequences? – More mistakes? – Duplication of work? – ... • Additional complexity … – Need to add these aspects to the model 49

Exploring online SFD simulations • https://insightmaker.com – Free & Open – Supports Collaboration – Huge repository of models you can play with 50

Exploring online SFD simulations https://insightmaker.com/insight/12842/2014-Weather-Climate-E xtreme-Loss-of-Arable-Land-and-Ocean-Fertility-The-World3-Mo del-Forecaster 51

Exploring online SFD simulations https://insightmaker.com/insight/101411/Air-Transport-Causal-Loop-Diagram 52

Exploring online SFD simulations https://insightmaker.com/insight/7682/Implementing-Chronic-Care-Management 53

Exploring online SFD simulations https://insightmaker.com/insight/188271/Upgrade-of-Kermack-McKendrick-Epidemic-SIR-Infectious-Disease-Model-Metrics-by-Guy-Lakeman 54