Training is a critical issue for operators responsible for the safe and efficient operation of large-scale complex dynamic systems. This paper proposes and articulates a set of requirements for an intelligent tutoring system. The requirements specify what (instructional content) and how (instructional strategies) to teach a novice operator to supervise and control a complex dynamic system. The instructional content teaches system structure and behavior (i.e., declarative knowledge), system procedures (i.e., procedural knowledge), and how to use this declarative and procedural knowledge to manage a complex dynamic system in real time (i.e., operational skill). Using the underlying representations of the operator function model (OFM) and OFMspert, the OFM's computational implementation. GT-VITA (Georgia Tech Visual and Inspectable Tutor and Assistant) realizes these requirements. As a proof-of-concept demonstration, an instance of the generic GT-VITA tutoring architecture was implemented for satellite ground controllers. The empirical evaluation, utilizing NASA satellite ground control personnel, showed that GT-VITA was a flexible and useful training system. In fact, NASA has adopted VITA as the foundation for required training for all satellite ground control personnel. In addition to an intelligent tutoring system architecture, by using and extending the operator function model and OFMspert, GT-VITA demonstrates a robust methodology for conceptualizing the tutor-aid paradigm. The tutor-aid paradigm defines a conceptual framework in which learning with a intelligent tutor gradually becomes collaboration with an intelligent associate. Using the same structures (i.e., OFM and OFMspert) and the same domain knowledge, GT-VITA specifies a tutor and GT-MOCA (Jones and Mitchell, 1995) specifies an aid.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>