上海交通大学：《系统思考与科学决策 Systems Thinking and Scientific Decision-making》课程教学资源（讲义）Lecture 2 System Dynamics（2/2）

System Dynamics ll Huang Dan 7 March,2017 上游充通大￥ Shanghai Jiao Tong University

System Dynamics II Huang Dan 7 March, 2017

Final Group Assignment Requirements: Refer to course ftp site Logistics: Submit your team members March 21 Final presentation May 2

Final Group Assignment Requirements: Refer to course ftp site Logistics: • Submit your team members March 21 • Final presentation May 2

Last Class Project problems viewed dynamically Understanding dynamics:the system dynamics methodology

Last Class  Project problems viewed dynamically  Understanding dynamics: the system dynamics methodology

System Dynamics Viewpoint While external events are a fact of life on projects,project performance problems are fundamentally dynamic problems that result from attempts to manage in face of change and uncertainty. 5

5 System Dynamics Viewpoint While external events are a fact of life on projects, project performance problems are fundamentally dynamic problems that result from attempts to manage in face of change and uncertainty

What Causes Dynamics? All dynamics are driven by Accumulation processes Feedback processes 6

6 What Causes Dynamics? All dynamics are driven by –  Accumulation processes  Feedback processes

Stock 又 inflow outflaw 7

7

What Causes Dynamics? All dynamics are driven by -Accumulation processes Feedback processes 8

8 What Causes Dynamics? All dynamics are driven by –  Accumulation processes  Feedback processes

Causal loop diagrams--causal links An arrow with a positive sign (+)means that,all else remaining equal,an increase(decrease)in the first variable increases(decreases)the second variable above (below)what it would otherwise have been. Resources Work Rate 9

Causal loop diagrams -- causal links An arrow with a positive sign (+) means that, all else remaining equal, an increase (decrease) in the first variable increases (decreases) the second variable above (below) what it would otherwise have been. Resources Work Rate + 9

Causal loop diagrams--causal links An arrow with a positive sign (+)means that,all else remaining equal,an increase (decrease)in the first variable increases(decreases)the second variable above (below)what it would otherwise have been. Resources Work Rate An arrow with a negative sign(-)means that,all else remaining equal,an increase (decrease)in the first variable decreases (increases)the second variable below (above)what it otherwise would have been. Fatigue Productiv ity 10

Causal loop diagrams -- causal links An arrow with a positive sign (+) means that, all else remaining equal, an increase (decrease) in the first variable increases (decreases) the second variable above (below) what it would otherwise have been. An arrow with a negative sign (-) means that, all else remaining equal, an increase (decrease) in the first variable decreases (increases) the second variable below (above) what it otherwise would have been. Resources Work Rate + Fatigue Productivity - 10

Inventory Production Shipments Work Rate Resources Productivity Births Population Deaths 11

Inventory Production Shipments Work Rate Resources Productivity Population Births Deaths 11