Scheduling Problem. This optimization tool focuses on addressing the transportation plan for the factory for a given resources schedule. In this solution the resources (machines) schedule is already defined by another agent while this agent is assigned with the transportation tasks associated with the resource tasks. The objective of this agent is to minimize the earliness/ lateness of delivering the material to the location of the resource that the resource task is going to be performed. It is important to highlight that this scheduling solution requires the existence of the resources schedule in order for this solution to work. This introduces the following limitations: In re-scheduling/ dynamic scheduling solutions the agent waits for resources planning to be completed before starting any optimization services. This requires a more flexible response delay for the system. Since the two schedules are split into two different problems there is no guarantee in the inheritance between the material delivery deadlines and the actual time required to deliver the material, considering AGVs availability, transportation distances, and release time of the material. This could usually introduce lateness in the production schedule. However, dealing the transportation problem independently, as presented in the figure bellow provides the following advantages: The agent requires less time to schedule any given problem, in comparison to the integrated scheduling solution. There are lower resources utilization requirements which makes the algorithms easier to run on local computational resources of the factory. There is a lower number of decision variables which makes the algorithm more accurate on approximating the optimal value of the objective function Figure 41 High-level design of the proposed scheduling problem
Scheduling Problem. Similar to previous scheduling methodology for transportation vehicles, this scheduling agent is used in order to give a model-based optimization solution. The difference between this solution and the one in section 3.3.5 is that it provides the flexibility in describing the position of the vehicles rather than the transportation that are assigned with. This gives the ability to have a dynamic behaviour even if no tasks have allocated to the AGV. The proposed modelling provides the following advantages and disadvantages The position of the AGV will be defined more flexibly giving the ability to move AGVs without assigning any tasks which can allow handle factory spaces and processes better. The AGV could handle more than one items at the same time in cases where the environment constrains allow it The complexity of the model increases, and more flexible response timeslots are required
