Chapter 3 - Modelling and Simulation Flashcards
Definition: System
A collection of entities that interact together over time to accomplish one of more goals
Definition: model
An abstract representation of a system, usually containing relationships which describe a system in terms of state, entities, and their attributes, sets, processes, events, activities, and delays
Definition: System State
A collection of variables that contain all the information necessary to describe the system at any time
Definition: Entity
Any object or component in the system which requires explicit representation in the model
Definition: Attributes
The properties of a given entity
Definition: List
A collection of (permanently or temporarily) associated entities, ordered in some logical fashion (ex. FCFS or by priority)
Definition: Event
An instantaneous occurrence that changes the state of a system (ex. arrival or departure of a customer)
Definition: Event Notice
a record of an event to occur at the current or some future time, along with any associated information necessary to execute the event (at minimum includes the event type and event time)
Definition: Event list
A list of event notices for future events, ordered by time of occurrence (also know as the future event list (FEL))
Definition: Activity
A duration of time of specified length (ex. service time or inter-arrival time), which is known when it begins (may be in terms sof statistical distribution)
Definition: Delay
A duration of time of unspecified indefinite length which is not known until it ends (ex. delay while waiting in queue)
(Delay is undesired)
Definition: Clock
A variable representing simulated time
Primary vs Secondary event
primary = completion of an activity (end of unconditional wait)
secondary = completion of a delay (end of conditional wait)
