Logos: a constraint-directed reasoning shell for operations management

A description is given of the Logos reasoning shell, an expert system that performs reactive scheduling, i.e. reschedules operations in the context of new information. Logos' constraint system supports the use of temporal constraints as well as the need to add and retract constraints incrementally. Logos' problem-solving approach is discussed and constraint-based reasoning and dynamic modeling, both of which are used by Logos, are examined. Some current applications are described. >