Symbol elements are graphical elements that can connect to the other core simulation elements. They are useful for aligning Silico models closely to other visualisations, particularly process maps.
To add a Symbol element in Silico’s model builder, right-click and select “Create Symbol” or use the keyboard shortcut “Y”. By default, Symbol elements appear as a circle with an “x” icon.
Clicking on a Symbol element opens its inspector, which allows altering its shape, icon, and label. Symbol elements can take the forms of circles, diamonds, and squares. The icon displayed in the centre of the Symbol element can also be adjusted. Silico currently supports the most common icons used in the two major process mapping standards – Business Process Model and Notation (BPMN) and Event-Driven Process Chains (EPC). The shape and icon are compulsory settings, and users can add an optional label.
Flows can be connected to a Symbol element as in- and outflows. Moreover, connectors between Symbol elements and Stocks and Variables can be created in either direction. Thereby, the Symbol element allows modellers to align their Silico models’ structure with existing visualisations, such as a process map.
For example, a Symbol element may be used in a hiring process model, in which applications are reviewed and then rejected or accepted. Process maps may represent this structure through three activities or events connected by an OR/exclusive gateway – usually an “X” in a diamond shape. The Symbol element replicates this particular and other structures.
The connections between the Symbol elements and the three core simulation elements do not influence calculations. Flows connected to a Symbol element behave as if the side of the flow connected to the Symbol element is not connected to anything. Incoming connectors do not influence the Symbol element as it has no equation, and outgoing connectors do not affect other simulation elements because the Symbol element has no value that could be used in their equations.
This provides modellers with the flexibility to create equations flexibly and as required. For example, the equation set for the flow “Applications Accepted” may be “Applications Reviewed”*”%Accepted”. Instead of visually connecting these two elements via a connector, the “% Accepted” variable is connected to the Symbol element. This structure better aligns with an underlying process map and may help process specialists working with the model to understand it better.