Development of Interactive Facilities in a Knowledge-Based Scheduling Framework

摘要

This contribution presents an interactive scheduling framework aimed at supporting the construction and evolutionary modification of schedules by means of mouse-and-click actions over Gantt diagrams. The proposed approach pursues the engagement of the user in the process of maintaining a schedule in a dynamic environment, in a non-disruptive fashion, by providing him/her with interactive facilities for schedule modification. The proposed framework relies on an explicit object-oriented representation of the schedule and supports, up to now, three categories of user-driven revision actions: operation-based, production order-based and resource-based schedule modification actions. Before executing any action proposed by the scheduler possible conflicts are checked. A rich underlying representation of the domain layer keeps track of different kinds of soft and hard constraints and prevents users from possible mistakes. Indeed, any manipulation is done under the supervision of consistency enforcing methods that send warning messages in case soft-constraints are violated and forbid modifications that infringe hard constraints. Consequences of accepted revision actions are propagated and immediately depicted. During this constraint propagation phase an opportunistic approach is adopted to improve the schedule's quality.