Maintaining consistency in a Quantitative Time Manager

A module for quantitative temporal management is presented which can be easily connected with different problem solving architectures. Particular attention has been devoted to planning and scheduling problems in realistic domains. The module allows for an incremental constraint posting approach for building solutions. After introducing the consistency-checking problem in quantitative temporal networks, a correct and complete algorithm for constraint propagation is described, and a sufficient condition for inconsistency is also presented as useful to improve the algorithm. Moreover a repropagate operator is given which is used to re-establish a consistent network when a given constraint set is relaxed