title: On-the-fly scheduling as a manifestation of partial-order planning and dynamic task values.
abstract: OBJECTIVE
  The aim of this study was to develop a computational account of the spontaneous task ordering that occurs within jobs as work unfolds ("on-the-fly task scheduling").
  
  
  BACKGROUND
  Air traffic control is an example of work in which operators have to schedule their tasks as a partially predictable work flow emerges. To date, little attention has been paid to such on-the-fly scheduling situations.
  
  
  METHODS
  We present a series of discrete-event models fit to conflict resolution decision data collected from experienced controllers operating in a high-fidelity simulation.
  
  
  RESULTS
  Our simulations reveal air traffic controllers' scheduling decisions as examples of the partial-order planning approach of Hayes-Roth and Hayes-Roth. The most successful model uses opportunistic first-come-first-served scheduling to select tasks from a queue. Tasks with short deadlines are executed immediately. Tasks with long deadlines are evaluated to assess whether they need to be executed immediately or deferred.
  
  
  CONCLUSIONS
  On-the-fly task scheduling is computationally tractable despite its surface complexity and understandable as an example of both the partial-order planning strategy and the dynamic-value approach to prioritization.
authors.forename: Samuel D
authors.initials: SD
authors.lastname: Hannah
authors.forename: Andrew
authors.initials: A
authors.lastname: Neal
mesh_terms: D001359:Aviation; D003657:Decision Making; D006801:Humans; D008960:Models, Psychological; D011340:Problem Solving; D013647:Task Performance and Analysis; D013997:Time Factors; D057188:Workflow; D016526:Workload