# Simulation

- Used to study complex systems
- The development of a
**model** of a **complex system** and the experimental manipulation to observe results
**System**
- Groups of objects interacting in some way
- Dynamic, interactive, and complicated

**Model**
- An abstraction of a real system
- Representation of the objects within a system and the rules that govern those objects

- Can be a
**continuous** or **discrete-event** simulation
**Continuous**
- Time is continuous
- Changes are expressed in terms of a set of differential equations reflecting the relationships among the set of characteristics
- Characteristics are chosen to model the system must be understood with mathematics

- Frequently used by engineers and economists

**Discrete-event**
- Made up of entities, attributes, and events
- Entity
- Some object in the real system

- Event
- Interaction between entities