What is a system?
A collection of interrelated components that collectively achieve a goal that cannot be achieved by any of its subparts.
Systems in which the properties of their components do not change over time in order to meet the goal
and Dynamic Systems:
Systems in which the properties of their components change over time to meet the goal.
Goal is what the system is designed and engineered to archive.
Structure(or system architecture) is how the components are ornganized and interconnected to achieve the goal.
Behavior is how the properties of the components change in time as the system…
The boundary of the system defines its interaction with its environment.
Open and Closed (Feedback) systems
Open system: future action is guided by exogenous variables(a vehicle without the driver is an open system)
Future action is guided by results from past action. Output feeds back to input.(a vehicle with the driver is a closed system.
A system whose interconnections between subparts are so dense or ambiguous that it is practically impossible to inger the system’s. – like Internet(too complex to describe)
Feedback system is closed
Why we have to have a model of simulation?
- understanding the system
- Predict what-if senario
(only for dynamic and not to static system)
- casual loop analysis
- stock & flow models
Casual loop analysis(Understanding structure)
If we do something, can we actually solve a problem?
Positive and negative feedback loop:
Flow and stocks:
Early simulation machine: Moniac, factory model etc.
Problems of top-down system dynamic analysis:
if we start to think from a bike sharing system, round trip system. Multi-agent system/
Bottom up approach Emerging behavior:
- Create and define breeds of agents
- a main loop iterates infinitely
- On each step of the loop, an observer asks each agent to do something