This section explains the key components you’ll find inside a simulation model.

2.1 Entity & Attributes

An Entity is an object in your simulation that can be static or dynamic. Think of it as a noun in your model’s world—a person, a product, a vehicle.

Attributes are the local values or properties that describe a specific entity. They give entities their unique characteristics.

For example, in a model of an assembly line, a product would be an entity, and its part_number or assembly_status would be its attributes.

2.2 Resources

A Resource is an entity that provides a service to other entities. A resource is something an entity needs to use to get a task done, and if it’s not available, the entity might have to wait in a queue. Examples include a machine on an assembly line, a server in a computer network, or a cashier in a store.

With an understanding of a model’s internal parts, it’s critical to ensure the model itself is a correct and accurate representation of reality.