Simulation-Based Development of Internet of Cyber-Things Using DEVS
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThis manuscript presents an in-depth study on the use of the DEVS (Discrete Event System Specification) formalism as a modeling and simulation framework for the Internet of Cyber-Things (IoCT), a convergence of IoT and cyber-physical systems. The authors argue that DEVS fulfills key requirements for IoCT system development, specifically model expressiveness and model continuity. These claims are supported through a range of illustrative examples, including home automation, smart grid monitoring, actuation conflict resolution, and unmanned swarm systems. The paper also highlights the value of the System Entity Structure (SES) in managing complexity through modular, hierarchical design.
The topic is relevant, and the manuscript offers a clear conceptual framework along with practical implementation evidence. However, the manuscript suffers from several issues, such as over-reliance on prior works by the authors, insufficient comparison with alternatives, and limited critical discussion, etc. Therefore, the reviewer recommends major revision at this stage.
Here are the detailed comments and concerns from the reviewer.
- Over-reliance on prior work by the authors: A significant number of the case studies and examples presented are derived from the authors’ own previous research. While these examples are informative, the manuscript would benefit from the inclusion of third-party use cases or validation studies. This would help demonstrate broader applicability.
- Limited critical discussion: The discussion section currently lacks sufficient analysis of the limitations or challenges of applying DEVS in large-scale or industrial-grade IoCT deployments. Specific issues such as toolchain maturity, usability, learning curve for new users, and interoperability with existing industrial systems could be addressed to provide a more balanced and informative perspective.
- Comparison with alternative modeling formalisms: Although Appendix A and Section 5.2 introduce other modeling approaches, the comparisons are largely qualitative. The manuscript would be strengthened by including more concrete and quantitative comparisons, such as differences in simulation efficiency, scalability, ease of model reuse, or real-time performance. Tabulated benchmarks or side-by-side examples could be effective here.
- Figure readability and quality: Several figures (e.g., Figures 2, 11, and 12) suffer from low resolution and/or small font sizes, making them difficult to read. The authors should consider enhancing the visual quality of all figures by improving resolution, increasing font sizes, and ensuring consistency in formatting to enhance clarity and presentation quality.
Author Response
The topic is relevant, and the manuscript offers a clear conceptual framework along with practical implementation evidence. However, the manuscript suffers from several issues, such as over-reliance on prior works by the authors, insufficient comparison with alternatives, and limited critical discussion, etc. Therefore, the reviewer recommends major revision at this stage.
Here are the detailed comments and concerns from the reviewer.
- Over-reliance on prior work by the authors: A significant number of the case studies and examples presented are derived from the authors’ own previous research. While these examples are informative, the manuscript would benefit from the inclusion of third-party use cases or validation studies. This would help demonstrate broader applicability.
- Limited critical discussion: The discussion section currently lacks sufficient analysis of the limitations or challenges of applying DEVS in large-scale or industrial-grade IoCT deployments. Specific issues such as toolchain maturity, usability, learning curve for new users, and interoperability with existing industrial systems could be addressed to provide a more balanced and informative perspective.
- Comparison with alternative modeling formalisms: Although Appendix A and Section 5.2 introduce other modeling approaches, the comparisons are largely qualitative. The manuscript would be strengthened by including more concrete and quantitative comparisons, such as differences in simulation efficiency, scalability, ease of model reuse, or real-time performance. Tabulated benchmarks or side-by-side examples could be effective here.
- Figure readability and quality: Several figures (e.g., Figures 2, 11, and 12) suffer from low resolution and/or small font sizes, making them difficult to read. The authors should consider enhancing the visual quality of all figures by improving resolution, increasing font sizes, and ensuring consistency in formatting to enhance clarity and presentation quality.
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Answer:
We thank the reviewer for the constructive and detailed feedback. We have carefully revised the manuscript to address all the concerns raised. Below, we provide a point-by-point response to each comment, along with the actions taken in the revised version.
Comment 1: Over-reliance on prior work by the authors
A significant number of the case studies and examples presented are derived from the authors’ own previous research. The manuscript would benefit from the inclusion of third-party use cases or validation studies.
Response:
We fully agree with this observation. To address it, we have integrated several external case studies that demonstrate the applicability of DEVS in diverse and independent contexts:
- We included the work of Bonaventura et al. [1], which applied DEVS to the ATLAS data acquisition system at CERN. This large-scale, real-time system validated DEVS simulation results through physical deployment, demonstrating its predictive power and performance benefits in high-frequency environments.
- We also referenced the work of Xie et al. [2], who used DEVS in conjunction with the X language for industrial product design. Their approach enabled seamless transition from modeling to semi-physical simulation, validated through a mechanical arm case study.
- Additionally, we discussed the modeling architecture proposed by Yuan et al. [3], which contrasts with DEVS by using behavior trees and publish-subscribe mechanisms. This comparison highlights the broader modeling landscape and supports the general relevance of the DEVS approach.
These additions help demonstrate the broader applicability and relevance of DEVS beyond our own work.
Comment 2: Limited critical discussion
The discussion section currently lacks sufficient analysis of the limitations or challenges of applying DEVS in large-scale or industrial-grade IoCT deployments.
Response:
We have expanded the discussion section to include a more critical analysis of DEVS in industrial and large-scale contexts. Specifically, we now address:
- The challenges of toolchain maturity and the learning curve for new users.
- The limitations of static port-based coupling in DEVS, and how alternative approaches (e.g., publish-subscribe architectures) attempt to overcome these issues.
- The interoperability of DEVS with industrial standards such as SysML and AADL, and the trade-offs involved.
These additions provide a more balanced and nuanced view of DEVS’s strengths and limitations.
Comment 3: Comparison with alternative modeling formalisms
The comparisons are largely qualitative. The manuscript would be strengthened by including more concrete and quantitative comparisons.
Response:
We have enriched the comparison with alternative modeling formalisms by:
- Adding a detailed discussion of the architecture proposed by Yuan et al. [3], which uses behavior trees and dynamic interest matching to enhance extensibility and reusability.
- Highlighting specific limitations of Petri nets, state machines, and SysML in terms of modularity, concurrency, and real-time execution.
- Including a new table (Table 3) that compares DEVS with other formalisms across criteria such as simulation efficiency, model reuse, and real-time support.
These enhancements provide a clearer and more structured comparison framework.
Comment 4: Figure readability and quality
Several figures suffer from low resolution and/or small font sizes.
Response:
We have revised all figures mentioned (Figures 2, 11, and 12) to improve resolution and font size. We also ensured consistent formatting across all visual elements to enhance clarity and presentation quality.
We thank the reviewer again for the valuable feedback, which has helped us significantly improve the quality and clarity of the manuscript.
Reviewer 2 Report
Comments and Suggestions for AuthorsThe paper addresses the important convergence of IoT and CPS, introducing the "Internet of Cyber-Things" . The focus on simulation-based development and the DEVS formalism is highly relevant for modern complex, networked systems. The authors thoroughly explain the DEVS formalism, SES, and their roles in IoCT system design. The coverage of model expressiveness and model continuity as essential requirements for IoCT development is well-motivated and justified. Following are my major concerns on the paper:
- While the case studies and example applications are descriptive, the paper would benefit from including more quantitative results (e.g., simulation benchmarks, performance metrics). If possible, add data, charts, or tables that empirically validate the claimed advantages of DEVS over alternatives.
- The authors may consider tightening the narrative by focusing more on how DEVS uniquely addresses IoCT challenges, rather than reviewing background material at great length.
- While some examples mention real deployments (e.g., smart parking in Bastia), it would strengthen the paper to include more details or data from such deployments. How did DEVS contribute to solving real engineering challenges? Were there measurable improvements
Author Response
The paper addresses the important convergence of IoT and CPS, introducing the "Internet of Cyber-Things" . The focus on simulation-based development and the DEVS formalism is highly relevant for modern complex, networked systems. The authors thoroughly explain the DEVS formalism, SES, and their roles in IoCT system design. The coverage of model expressiveness and model continuity as essential requirements for IoCT development is well-motivated and justified. Following are my major concerns on the paper:
- While the case studies and example applications are descriptive, the paper would benefit from including more quantitative results (e.g., simulation benchmarks, performance metrics). If possible, add data, charts, or tables that empirically validate the claimed advantages of DEVS over alternatives.
- The authors may consider tightening the narrative by focusing more on how DEVS uniquely addresses IoCT challenges, rather than reviewing background material at great length.
- While some examples mention real deployments (e.g., smart parking in Bastia), it would strengthen the paper to include more details or data from such deployments. How did DEVS contribute to solving real engineering challenges? Were there measurable improvements
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We sincerely thank Reviewer 2 for their constructive and insightful comments. We have carefully revised the manuscript to address each of the points raised. Below is a summary of the changes made in response to your suggestions:
Comment 1: Include more quantitative results
Reviewer’s comment:
“While the case studies and example applications are descriptive, the paper would benefit from including more quantitative results (e.g., simulation benchmarks, performance metrics).”
Response:
We have added quantitative results in Section 4.1 (Home Automation), based on recent work by Fazel and Wainer (2024), showing improvements in precision (+22.86%), recall (+24.05%), and F1-score (+23.45%) compared to traditional classification methods. Additionally, Section 4.4 (Smart Parking) now includes a table summarizing neural network accuracy across simulation phases, culminating in 96.6% accuracy on simulated data. These additions provide empirical support for the advantages of DEVS.
Comment 2: Tighten the narrative and reduce background
Reviewer’s comment:
“The authors may consider tightening the narrative by focusing more on how DEVS uniquely addresses IoCT challenges, rather than reviewing background material at great length.”
Response:
We have restructured Section 2 to focus on the positioning of DEVS within the broader IoT modeling landscape. Detailed explanations of DEVS and SES have been moved to Appendix A. We also added a comparative analysis of alternative modeling formalisms (FSMs, Petri Nets, SysML) in Appendix B, referenced from the main discussion in Section 5.
Comment 3: Provide more details on real deployments
Reviewer’s comment:
“While some examples mention real deployments (e.g., smart parking in Bastia), it would strengthen the paper to include more details or data from such deployments.”
Response:
Section 4.4 has been significantly expanded to describe the real-world deployment in Bastia, France, involving over 450 sensors and more than one million parking events. We included a table showing the evolution of model accuracy, and a figure illustrating the mobile application used in the deployment. These additions demonstrate how DEVS supported both simulation and operational phases of the smart parking system.
We hope these revisions address your concerns and improve the clarity and impact of the manuscript. Thank you again for your valuable feedback.
Reviewer 3 Report
Comments and Suggestions for AuthorsThis review introduces the capabilities of DEVS, including its modular expressivity and development continuity, as a simulation-based development language for the Internet of Things (IoCT). It includes several examples to demonstrate its broad applicability to IoCT systems. It also demonstrates the added value of the System Entity Structure (SES) in enhancing expressivity, scalability, and flexibility in IoCT system design. Overall, the article has several issues, particularly with writing and organization of ideas.
1. The type of this paper is "Review," but in the manuscript, the authors write it as "Article." This is very confusing. Please address this.
2. The overall objective is unclear in the abstract. Please clearly state the objective of this review in concise terms.
3. In the abstract, line 8, "Internet of Things (IoCT))," please update the abbreviation to "(IoT)"
4. In the abstract (Internet of Things (IoT) is about networking smart devices to share information), this definition is extremely succinct and inaccurate.
5. The possessive pronoun "we" is mentioned 22 times in the manuscript. In my opinion, it's not advisable to repeat possessive pronouns too often in scientific writing. Please address this.
6. The introduction of the abstract is poor. Please rewrite it in a more professional manner to highlight the novelty of this paper and its importance to the scientific community. You say, "We will present," "We will explain," "We will demonstrate," and so on. You did not provide anything that indicates the outcome of this proposal or the importance of the paper to the scientific community.
7. Line 9, "using DEVS (Discrete Event System Specification))," is the abbreviation placed in parentheses.
8. The abstract should clearly indicate the novelty of integrating the Internet of Things (IoT) and CPS within the Internet of Cyber-Things (IoCT) framework.
9. “Simulation-based development” could be explained more as a methodology than just a process.
10. It would be useful to summarize the benefits of DEVS in the abstract’s concluding sentence.
11. The studies included in this review are insufficient; more recent studies should be cited.
12. The paper’s depth in explaining the DEVS architecture is appreciated, but technical terminology could be simplified for broader accessibility.
13. Lines 330 and 331, (Figure 5 shows the custom ACM design process that includes the following levels: 330
Figure 5 illustrates a custom ACM design process organized into three main levels: ) Is this a repetition!!!
13. Figures 12 and 13 are of very poor quality.
14. At the end of the caption, Figure 13, (This SES is described by the text in Figure 14), this is a scientifically weak formulation.
15. The paper needs to raise the linguistic level greatly, as well as organizing the paper and highlighting its novelty and importance to the scientific community.
Comments on the Quality of English LanguageThe paper needs to be rewritten and the linguistic level raised.
Author Response
This review introduces the capabilities of DEVS, including its modular expressivity and development continuity, as a simulation-based development language for the Internet of Things (IoCT). It includes several examples to demonstrate its broad applicability to IoCT systems. It also demonstrates the added value of the System Entity Structure (SES) in enhancing expressivity, scalability, and flexibility in IoCT system design. Overall, the article has several issues, particularly with writing and organization of ideas.
1. The type of this paper is "Review," but in the manuscript, the authors write it as "Article." This is very confusing. Please address this.
2. The overall objective is unclear in the abstract. Please clearly state the objective of this review in concise terms.
3. In the abstract, line 8, "Internet of Things (IoCT))," please update the abbreviation to "(IoT)"
4. In the abstract (Internet of Things (IoT) is about networking smart devices to share information), this definition is extremely succinct and inaccurate.
5. The possessive pronoun "we" is mentioned 22 times in the manuscript. In my opinion, it's not advisable to repeat possessive pronouns too often in scientific writing. Please address this.
6. The introduction of the abstract is poor. Please rewrite it in a more professional manner to highlight the novelty of this paper and its importance to the scientific community. You say, "We will present," "We will explain," "We will demonstrate," and so on. You did not provide anything that indicates the outcome of this proposal or the importance of the paper to the scientific community.
7. Line 9, "using DEVS (Discrete Event System Specification))," is the abbreviation placed in parentheses.
8. The abstract should clearly indicate the novelty of integrating the Internet of Things (IoT) and CPS within the Internet of Cyber-Things (IoCT) framework.
9. “Simulation-based development” could be explained more as a methodology than just a process.
10. It would be useful to summarize the benefits of DEVS in the abstract’s concluding sentence.
11. The studies included in this review are insufficient; more recent studies should be cited.
12. The paper’s depth in explaining the DEVS architecture is appreciated, but technical terminology could be simplified for broader accessibility.
13. Lines 330 and 331, (Figure 5 shows the custom ACM design process that includes the following levels: 330
Figure 5 illustrates a custom ACM design process organized into three main levels: ) Is this a repetition!!!
13. Figures 12 and 13 are of very poor quality.
14. At the end of the caption, Figure 13, (This SES is described by the text in Figure 14), this is a scientifically weak formulation.
15. The paper needs to raise the linguistic level greatly, as well as organizing the paper and highlighting its novelty and importance to the scientific community.
Comments on the Quality of English Language
The paper needs to be rewritten and the linguistic level raised.
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Answer:
We sincerely thank the reviewer for the detailed and constructive feedback. All comments were carefully considered, and the manuscript has been substantially rewritten to address the concerns raised. These revisions have significantly improved the clarity, structure, and scientific quality of the paper. Below, we provide a point-by-point response to each comment:
1. Paper Type ("Review" vs. "Article")
✔️ The manuscript now consistently refers to the paper as a "Review" in both the title and metadata, eliminating the previous confusion.
2. Objective in the Abstract
✔️ The abstract has been rewritten to clearly state the objective:
“This review explores how the Discrete Event System Specification (DEVS) formalism can serve as a unified framework for designing, simulating, and implementing systems that combine IoT and CPS—referred to as the Internet of Cyber-Things (IoCT).”
3. Abbreviation Correction (IoCT → IoT)
✔️ The incorrect abbreviation in the abstract has been corrected. The term "Internet of Things (IoT)" is now used appropriately.
4. IoT Definition
✔️ The definition of IoT has been expanded for clarity and accuracy:
“The Internet of Things (IoT) connects physical devices equipped with sensors and software to collect and exchange data.”
5. Excessive Use of "We"
✔️ The manuscript has been revised to adopt a more neutral and academic tone. The use of the pronoun "we" has been significantly reduced throughout the text.
6. Abstract Introduction and Scientific Importance
✔️ The abstract has been rewritten to emphasize the novelty and scientific relevance of the work. It now highlights the integration of IoT and CPS into IoCT and the role of DEVS in supporting this convergence.
7. Parentheses Around DEVS
✔️ The abbreviation is now correctly formatted: “Discrete Event System Specification (DEVS)”
8. Novelty of IoT + CPS = IoCT
✔️ The abstract and introduction now clearly explain the novelty of the IoCT paradigm as a convergence of IoT and CPS, and the role of DEVS in supporting this integration.
9. Simulation-Based Development as a Methodology
✔️ The concept is now introduced as a structured methodology, not just a process:
“Simulation-based development is a structured approach that uses formal models to design and test system behavior before building the actual system.”
10. Summary of DEVS Benefits in the Abstract
✔️ The abstract concludes with a clear summary of DEVS’s advantages:
“The review concludes that DEVS offers a robust and flexible foundation for developing IoCT systems, supporting both expressiveness and seamless transition from design to real-world deployment.”
11. Inclusion of Recent Studies
⚠️ Several recent references (2023–2024) have been added to strengthen the review, particularly in the case studies and discussion sections. - Two reference (2024 & 2009) added in background section.
12. Simplification of Technical Terminology
✔️ The manuscript has been revised to improve accessibility. Complex terms have been clarified, and explanations have been added where needed, especially in Sections 2 and 3.
13. Repetition in Lines 330–331 (Figure 5)
✔️ This repetition has been noted and corrected.
13. Poor Quality of Figures 12 and 13
✔️ The figures have been updated to improve resolution and clarity.
14. Weak Caption for Figure 13
✔️ The caption has been rewritten to be more scientifically precise:
“Figure 13 employs the SES formalism to illustrate decentralized synchronization alternatives in USS.”
15. Linguistic Quality and Organization
✔️ The entire manuscript has been revised for improved language quality, clarity, and logical flow. The structure has been refined to better highlight the novelty and contributions of the paper.
We are grateful for the reviewer’s insightful comments, which have led to a significantly improved manuscript. We hope the revised version meets the expectations and is now suitable for publication.
Round 2
Reviewer 1 Report
Comments and Suggestions for AuthorsThe reviewer would like to thank the authors for the reply and revision. The manuscript has been improved, and it is suitable for publication.
Reviewer 3 Report
Comments and Suggestions for AuthorsAfter a thorough revision of the manuscript, the esteemed authors have addressed all the issues I raised previously. The manuscript has been significantly improved.
