Learn more about SimEvents

What Is an Entity?

Discrete-event simulations typically involve discrete items of interest. By definition, these items are called entities in SimEvents software. Entities can pass through a network of queues, servers, gates, and switches during a simulation. Entities can carry data, known in SimEvents software as attributes.

Note   Entities are not the same as events. Events are instantaneous discrete incidents that change a state variable, an output, and/or the occurrence of other events. See What Is an Event? for details.

Examples of entities in some sample applications are in the table.

Context of Sample Application	Entities
Airport with a queue for runway access	Airplanes waiting for access to runway
Communication network	Packets, frames, or messages to transmit
Bank of elevators	People traveling in elevators
Conveyor belt for assembling parts	Parts to assemble
Computer operating system	Computational tasks or jobs

A graphical block can represent a component that processes entities, but entities themselves do not have a graphical representation. When you design and analyze your discrete-event simulation, you can choose to focus on:

• The entities themselves. For example, what is the average waiting time for a series of entities entering a queue?

• The processes that entities undergo. For example, which step in a multiple-step process (that entities undergo) is most susceptible to failure?

Installing SimEvents Software

What Is an Event?

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