Week 1 Flashcards
Discrete-Event Simulation
Stochastic: contains random probabilistic elements
-> specify random variables: arrivals, duration of membership, claim size
Dynamic: the process evolves over time
Discrete: changes occur only at discrete points in time when events occur
DES Components
- Initialization routine: t=0
- Timing routine: choose next event time, then advance clock
- Event routine: logic for each event type
- Library routines: generate random variables
- Report generator: summary and report results at end
- Main program
(Like Assignment 1 - think!)
Components of a Queueing System
- Arrival process
- interarrivals Ai
- mean arrival time E(Ai)
- Service Mechanism
- service times Si
- mean service time E(S)
- number of servers c
- Queue discipline
- FCFS
- LCFS
- priority
Monte-Carlo Simulation
Stochastic: contains random probabilistic elements
Static: process does not occur over time
Take average of many random variables
Update Event List Question
Say when (t+a) you are generating next arrival (and where - think arrival or departure method) Say when (t+s) you are generating next departure Also state time and where for additional events!
Make sure you update all events in the simulation
Update Counter Variables Question
Example:
nCum = nCum + (t - ts)*n
-> current time - previous event time
State Variables
Contain the information on the system content
Event
Instantaneous occurrence that may change the state of the system