You usually define a human task for your human related activities.
Inside that task the users can introduce information that will be used lately by the process in order to decide which will be the next activities in the flow.
In jBPM5 you usually don't signal the process to continue. It is usually the user that ends a human task and based on the information provided inside the task the process definition choose between different paths to continue.
Is that what you are looking for?
Thanks for your quick response. At the moment we are not using human task but rather something similar (hard to explain but basically we are using a construct that represents a piece of work that needs to be done). I did a demo of JBPM 5 and the integration with our custom work constructs and a question I got was "is there a way to define what actions can be done on the process definition for the piece of work that needs to be done?" So what I was thinking was having a rules file that defines what actions are available for the work based on the state. is this a good approach?