DISJUNCTIVE CONSTRAINTS FOR MANUFACTURING SCHEDULING - PRINCIPLES ANDEXTENSIONS

Disjunctive constraints are widely used to ensure that the time interv als over which two activities require the same resource do not overlap in time. Two types of extensions of disjunctive constraints are propo sed: (1) extensions allowing the representation of more complex constr aints including activities that may or may not require the resource, ' state resources' to represent activities which may use resources only under specific conditions, and a mechanism to represent setup times be tween activities; (2) extensions of the disjunctive constraint propaga tion algorithm to deduce more precise time-bounds. These extensions ar e integrated in ILOG SCHEDULE, a C++ library for constraint-based sche duling.