Here's a quick/rough example showing how to use the predraw trigger to set the operator's location.
The model still needs the stopping/resuming of the item when it reaches the second decision point, and could use distAlong based estimation of where to walk to to meet the item rather than fixed offsets in this demonstration. You could add a 'token' label to the item when the token is created and remove it when the operation is done - this can then be tested at the stop dp point. You can add the conveyor resume item to the exisiting station-based process flow.
The preDraw trigger of the operator checks to see if it has an item label set to a value and if it does, calls it's label function "updateLoc". The code is on a label so that it's easy to invoke once the job has finished for the cases where the model is running as a replication without views; when you FastForward the model or are running fast and the view might skip some drawing frames.
assembly-line_jl.fsm