Re-scheduling of AGVs Steady State Flow

The paper's objective concerns assessing a mesh-like supply network of periodically acting local transportation modes from the perspective of possible re-scheduling the multimodal flows of jobs assigned to certain technological routes passing through common shared workstations. The considered reference model of a Material Transportation Network (MTN), where several heterogeneous means of material handling, e.g. AGVs, hoists, lifts, etc., interact with each other via common shared workstations, enables the formulation of scheduling and re-scheduling tasks in the context of a Periodic Vehicle Routing Problem. The main problem is in essence to identify conditions guaranteeing transient period free re-scheduling of cyclic steady state flows of multimodal processes and local transportation processes supporting their execution. Such sufficient conditions allows one to replace the exhaustive search for the admissible flows control by design of regular structure material handling system, i.e. to solve the considered class of re-scheduling problems online. The proposed methodology behind re-scheduling cyclic steady state production flows executed in regular-structure MTNs is clarified through multiple illustrative examples.