8.3.1 ARENA Template

The ARENA template consists of a collection of panels that are capable of modelling a broad range of systems. Each panel contains a set of modules each of which carry out a modelling operation. The panels are hierarchical in nature with some (e.g. COMMON.TPO) containing high level modules which are composed of more basic modules found in other panels (e.g. BLOCKS.TPO). The `SERVER' module in the COMMON panel will illustrate the idea. The Server module has been designed to represent a very common situation found in practice i.e. a time dependent activity which requires the presence of a resource (e.g. a bank clerk serving a customer or a drilling operation on a workpiece etc.)

In the Server module an arriving entity joins a queue until the required resources are available. It then seizes the appropriate combination of resources, delays by the processing time, releases the resources and then moves on to the next stage of the model.

In the lower level BLOCKS panel this set of modelling constructs would have to be implemented separately as shown in Fig. 8.1

Figure 8.1 : Low level implementation of a server

In addition the Server module also contains constructs to support animation and the possibility of subjecting the resource to a schedule of availability. To use the Server module you only have to fill in the relevant information in the associated dialog box (Fig. 8.2)

In many cases (the Server is one) sub forms allow the addition of further information. It is not necessary to add information to every field. In the majority of cases the default values can be accepted (See 8.4.1 as an example).

A nice feature of using panels is that in the same model you can mix modules from any panel. Specialist panels can be added to the ARENA system (e.g. Advanced Manufacturing) to customise the software for a particular applications area.