Gateway nodes allow you to evaluate different criteria to make decisions on which path(s) your workflow should follow – as well as how many instances are allowed to follow each optional path.
Appian provides the following types of gateway nodes:
|XOR||Exclusive Decision/Merge (Exclusive OR)||This type of gateway node allows one incoming path to continue, while excluding any others. It executes a single outgoing path determined by the conditions you set.|
|OR||Inclusive Decision/Merge||This type of gateway directs incoming flows to one of many possible output paths, based on the condition(s) you set.|
|COMPLEX||Complex Decision/Merge||This type of gateway allows you to selectively accept (or restrict) incoming paths and evaluate rules to determine outgoing paths. For example, you can restrict the node to accept only the first 3 out of 4 incoming paths, or require input from certain nodes before continuing. Outgoing paths can be configured in the same manner as other gateway nodes.|
|AND||Parallel Fork/Join||This type of gateway directs all incoming workflow(s) to all of the possible branches. If more than one incoming path is used, all incoming paths must reach the node before the process can continue. It can also be used to join all incoming paths into a single workflow.|
To access a gateway node:
Select the Gateways node category. The gateway nodes are displayed.
Gateway names displayed on the designer canvas can be edited inline by clicking the name. When editing a gateway name inline, it can be styled using the Font Palette.
Font Paletteis not displayed, select Tools > Show Font Palette.
Gateways can be used to route the process flow, or to create a loop among activities in a process model. If there are multiple incoming paths to a gateway, and a loop involving the gateway is established in your process model, the gateway only resets itself when all incoming paths have been activated.