Multivehicle Point-to-Point Network Problem Formulation for UAM Operation Management Used with Dynamic Scheduling

Round 1

Reviewer 1 Report

This interesting case study aimed to introduce a new formulation of the multi-vehicle point-to-point network problem to be utilised in urban air mobility vertiport-to-vertiport network operations. The authors in this paper formulate multi-vehicle point-to-point network problem for urban air mobility operation management used with dynamic scheduling.

The authors of this study aimed to create propose a new formulation of the point-to-point network problem for urban air mobility vertiport-to-vertiport operation by introducing new constraints with aim to generate a dynamic arrival and departure schedule for different vertiports that can avoid collisions while increasing the numbers of vehicles.

The present study tried to improve a vehicle routing problem and their variants have previously been studied and applied in real-world situations with using require additional depot locations, and all the vehicles can travel to all of the locations. The results show that although the formulation satisfies the problem definition, the computation time increases exponentially with an increase in the problem size. The case study shows that the formulation for the speed variable is active only for the lower and upper bounds for dynamic scheduling, while the waiting time variable can be controlled between user-defined limits that can be applied to the management of vertiport-to-verti-port urban air operations.

The authors created a computational experiment to conduct using a mixed integer linear programming model in the Seoul area involving five vertiports, and total vehicle numbers of 10 and 15 are studied for point-to-point network urban air mobility operation with dynamic scheduling. 

The measurements and instruments used by the authors seem to be valid. The results are processed in detail with creating case studies and many calculations and graphical confirmation of results.

The discussion is a reasonable extent and includes the essential findings of the study. More literature can be added to the discussion, enriching the authors' arguments.

In view of the limitations of the results reported by the authors, I agree with the authors that will be to need the customers’ requirements for travel from one location to another to consider in the selection of different route constraints. 

Do the authors plan to supplement the model with customer travel requirements in the future?

The paper I evaluate positively because the case study solves a new routing problem based on a multi-vehicle point-to-point network, inspired by the characteristics of the TSP and multi-depot routing problem.  This case study created an optimum flight schedule with the most suitable corridors for travelling from one location to another. For this reason, a computational experiment can help practitioners to use dynamic scheduling for urban air mobility operation management satisfied the constraints on waiting time, speed and routing selection.

Author Response

The reviewer comments and revisions are attached to this email. 

Author Response File: Author Response.docx

Reviewer 2 Report

In my opinion, you have to rewrite the keywords to remove the compound ones and reduce them, as well as reduce the size of the abstract. In the introduction it is necessary to identify the main objective of the work, which is presumed in the title, as well as some secondary objective derived from it. In the figures and tables it is necessary to put the authorship and the source of elaboration. It jumps to the methodology without establishing hypotheses, H1, H2…etc. The data is poorly explained. It would be convenient to include more international jcr bibliography.   Otherwise the work is quite good, so congratulate the authors for its originality. Finally, it would be convenient to add more international jcr bibliography.

Comments for author File: Comments.pdf

Author Response

Reviewer comments and corrections for manuscripts are attached to this email.

Author Response File: Author Response.docx