Definition
Combined Simulation Models integrate both discrete-event and continuous modeling methodologies within a single system. They are used to represent systems where some variables change instantaneously (events) while others change continuously over time.
Why It Matters
It allows for accurate modeling of modern systems where software logic interfaces with physical reality, such as flight controllers or power grids.
Core Concepts
- Discrete Events: State changes at separate points in time (e.g., a truck arriving, a pallet being loaded).
- Continuous Flux: State changes constantly (e.g., fluid levels in a tank, temperature in a kiln, chemical concentrations).
- State Events: A discrete event triggered by a continuous variable crossing a threshold (e.g., turning off a pump when a tank is 95% full).
- Time Events: A change in the continuous process triggered by a scheduled discrete event (e.g., starting a furnace at 8:00 AM).