question

Easiest way to do this is going to be with the A* Navigator and the Elevator Bank object in the A* Library. The exact application will depend a little on how you are creating the Task Executer Flowitem; either as "People" objects using the Person module or creating them as Flowitems at a Source object. See the attached model for a representation of both approaches.

Either approach to will require A* Grid objects at all the Z-axis heights where the travelers can either get on or off the elevator and an Elevator Bank object whose four posts are tall enough to reach all the "floors". The Elevator Bank object will also need to be added to the "Members" properties of the A* Navigator object.

If you are creating your Task Executers as People (using the Create Person Activity), simply telling the travelers to move via the Person activities in Process Flow will cause them to use the elevator. These types of travelers are automatically added to the A* Navigator's members.

If you are creating travelers with a Source object they will need to be added yourself during a trigger event. Putting the following expression into a Source's OnCreation trigger will accomplish this:

contextdragconnection(item, Model.find("AStarNavigator"), "A");

You may use the Elevator's "Request List Pull Query" to help manage how requests on the elevator get fulfilled. In my example model I found that as long as there were elevator requests on the second floor it was very hard to fulfill requests from the third floor because the query prefers requests that have a shorter distance. So I added an "age" field to the List so requests could also be sorted based on who has been waiting longer for the elevator.

I also found that the default way the capacity of the elevator was being managed made the elevator overly full, so I set the "Traveler Capacity Usage" property of the elevator to 1 and the "Elevator Capacity" to 6 so that the max number of people in the elevator is always 6.

TE Flowitem Elevator Multiple Approaches.fsm