Discrete Event Simulation
DES models systems where state changes at discrete time points.
Core Concepts
Entities, attributes, activities, events, state variables.
Simulation Clock
Next-event time advance jumps to next scheduled event, skipping idle periods.
Event Scheduling
Future Event List (FEL) sorted by time. Remove earliest, advance clock, execute, update stats, repeat.
Single-Server Queue
On arrival: if idle, serve; else queue. On departure: if queue non-empty, serve next; else idle.
Simulation Tools
SimPy, Arena, AnyLogic, GPSS for DES. Animation, statistics, pre-built components.
Warm-Up
Initialisation bias requires warm-up period. Multiple replications provide confidence intervals.
Summary
DES models complex stochastic systems by processing events chronologically.