ABSTRACT
This chapter discusses the use of biomathematical modeling tools as fatigue countermeasure and the issues involving model development, methodology and validation. It explains the manager who would like to use a biomathematical model for guidance, for decision support as a fatigue management planning tool, and who additionally wants to know the constraints. The chapter reviews the history of models of human performance before making recommendations. The chapter suggests that fatigue modelers consider descriptive modeling strategies and strategies rooted in complexity science. The history of the effort to realistically model the conditions that lead to human fatigue impairment is not long and may have had its origin in aviation. Conceptual model validity can be considered a form of construct validity, a term that traditionally refers to the extent to which a measurement method or instrument measures what it is supposed to be measuring.
