SimEvents 3.1

Working with SimEvents

SimEvents provides a library of blocks for modeling the motion of entities in a system. You can model both simple and complex networks of queues and servers. By connecting gate and switching blocks you can establish paths along which entities can travel in response to events. These paths can include delays and selective switching criteria. Many parameters within SimEvents can be statistically determined to model probabilistic variations in the system.

SimEvents block library containing common elements for building discrete-event simulation models. Scopes let you view entity attributes and statistics.

Creating Entities and Setting Attributes

With SimEvents you can create entities in response to events or on a scheduled basis, where the time of generation can be controlled by a signal or a statistical distribution. You can give the entity attributes appropriate to your application, such as a destination address on a communication bus, processing times or delays for servers, or any relevant data. Attributes can also be vectors or matrices required to model larger payloads of data in packet-based systems. Attribute values can be modified during simulation based on an algorithm implemented as an Embedded MATLAB™ function. For example, a complex switching algorithm written as an Embedded MATLAB function can be a used in a SimEvents model that simulates the entire switch fabric.

Modeling Queues and Servers

SimEvents provides first-in, first-out (FIFO) and last-in, first-out (LIFO) queue blocks, as well as a priority queue block that sorts incoming entities based on the value of an attribute. Server blocks range from a single server with blocking to an infinite server that accepts all incoming entities. By combining the single server's preemption capability with the priority queue block, you can implement a variety of preemption policies.

Routing and Gating Entities

SimEvents routes or gates entities using switches that operate either deterministically, in response to input signals or attribute values, or statistically, based on a first-available-port, round-robin, or equiprobable switching criterion. By cascading these switches, you can form more complex switching arrangements. You can incorporate various gates to implement admission control procedures and manage entity movement in your model.