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.<>