← Dynamic Systems Engineering Foundations · Semester 1, Week 2
Thinking in Systems
Theme
Once we understand knowledge, we begin organizing reality into systems. Every field of engineering studies systems composed of interacting parts. Dynamic Systems Engineering extends this idea by emphasizing changing state, causal interactions, and feedback.
Learning Objectives
By the end of this week, students should be able to:
- Define a system.
- Identify system boundaries.
- Identify inputs and outputs.
- Identify state variables.
- Recognize feedback.
- Recognize constraints.
- Build a first-order system model.
Core Vocabulary
System · Subsystem · Environment · Boundary · Input · Output · State · State Variable · Feedback · Constraint · Controller · Disturbance · Emergence
Fundamental Principles
No system exists completely independently.
Choosing a system boundary determines what is considered internal and external.
Understanding a system requires describing its current state.
The individual components alone rarely explain the behavior of the whole system.
Without feedback, intelligent regulation is impossible.
Anchor Example — Thermostat
System: Room
Inputs: Desired temperature · Outside weather
Outputs: Heater state
State Variables: Current temperature · Target temperature
Feedback: Temperature measurement controls future heater behavior.
Anchor Example — Human Learning
System: Student
Inputs: Instruction · Practice · Feedback · Sleep · Motivation
Outputs: Performance · Retention · Problem-solving ability
State Variables: Knowledge · Confidence · Attention · Cognitive load
Feedback: Mistakes guide future learning.
Anchor Example — AI Assistant
System: Large Language Model
Inputs: Prompt · Retrieved knowledge · Conversation history
Outputs: Response · Explanations · Predictions
State Variables (conceptual): Current context · Estimated user intent · Active knowledge
Feedback: User corrections influence future interactions.
Anchor Example — Traffic
Inputs: Vehicle arrivals
Outputs: Vehicle departures
State Variables: Vehicle density · Average speed · Queue length
Feedback: Congestion changes future driver behavior.
Anchor Example — Small Business
Inputs: Customers · Capital · Employees · Materials
Outputs: Products · Services · Revenue
State Variables: Cash · Inventory · Reputation · Workforce
Feedback: Sales influence inventory, hiring, and marketing decisions.
AI Laboratory
Ask AI to model each anchor example using the following template: Purpose, Boundary, Inputs, Outputs, State Variables, Feedback, Constraints, Disturbances, Predictions. Compare the AI's model with your own and identify any missing variables or questionable assumptions.
Reflection Questions
- Where did I place the system boundary?
- What variables matter most?
- What variables did I ignore?
- How would changing the boundary change the model?
Assignment
Select one unfamiliar system — a hospital, ecosystem, sports team, or manufacturing process. Create a first-order systems model using the common Dynamic Systems Engineering template.
End-of-Week Competency
A successful student can represent a real-world system as interacting components with identifiable state variables, feedback loops, constraints, and measurable behavior, providing the foundation for causal reasoning in Week 3.