There are three types of plugins, Simulator, Checker and Algorithms. A plugin is build around two main classes: a Factory, and a Model/Requirement/Scheduler class.
The Factory can be seen as the plugin entry point. It implements methods to retrieve the plugin’s name and description. But its main task is to instantiate the class that is implementing the Simulator, the Checker or the Algorithm interface.
Models and requirements factories inherit from the AbstractModelFactory or AbstractRequirementFactory classes, that both implement the AbstractDataFactory interface. Algorithms factories inherit the InterfaceAlgorithmFactory.
PLASMA Lab plugin system use the Java Simple Plugin Framework. To load a plugin, the factory class must implement the Plugin interface and have the tag @PluginImplementation before the class declaration. More details and a 5 min tutorial can be found on their website: