Ergonomics Management Evaluation Model for Supply Chain: An Axiomatic Design Approach

Response to Reviewer 1 Comments

1.       Summary

We appreciate the time and effort you and the reviewers dedicated to providing feedback on our manuscript and are grateful for the insightful comments and valuable improvements to our paper.

We have incorporated most of the reviewers' suggestions, which are highlighted within the manuscript. Please see below, in blue, for a point-by-point response to the reviewers’ comments and concerns. All page numbers refer to the revised manuscript file with tracked changes. 

We hope that you will find our responses adequate.

2. Questions for General Evaluation

Reviewer’s Evaluation

Response and Revisions

Is the content succinctly described and contextualized with respect to previous and present theoretical background and empirical research (if applicable) on the topic?

Yes

Are the research design, questions, hypotheses, and methods clearly stated?

Yes

Are the arguments and discussion of findings coherent, balanced, and compelling?

Yes

For empirical research, are the results clearly presented?

Yes

Is the article adequately referenced?

Yes

Are the conclusions thoroughly supported by the results presented in the article or referenced in secondary literature?

Yes

3. Point-by-point response to Comments and Suggestions for Authors

Comments 1: How does the proposed Ergonomics Management Evaluation Model (EMEM) compare with existing ergonomics management models regarding practical implementation and effectiveness?

Response 1: Thank you for your question. As a response, the existing literature acknowledges the absence of an ergonomics management evaluation model (EMEM) for supply chains that could aid in achieving sustainability goals and facilitate a detailed evaluation of their interconnected links.

Regarding practical implementation and effectiveness, the EMEM presents similarities in the EMPr&Rq evaluated in the different models. Still, these were not designed to assess the entire supply chain. We can comment that the main contribution of the EMEM of the SC is to provide a structured framework to identify, evaluate, and improve the EMPr&Rq that impacts the productivity, safety, and well-being of workers along the entire supply chain. This assessment approach proposes a macroergonomic analysis of the supply chain. It establishes an action plan considering the highest priority risks or issues to guide decision-makers in implementing ergonomic improvement actions. In addition, having an index such as the EMI provides evidence of the level of compliance with the EMPr&Rq through a quantitative indicator that can be recalculated according to the progress of compliance of the evaluated system, so it is considered an improvement parameter for decision-making. The following is a comparison of the different ergonomic management models with the EMEM:

Neves et al. [60] propose an ergonomics management model based on good practices for large industrial companies. These practices are related to the processes of 1) Management Commitment, 2) Piloting, 3) Integration into Projects, 4) Development of Competence, 5) Communication and Documentation, 6) Auditable Standard, 7) Continuous Assessment, and 8) Network Creation. In contrast, the EMEM proposed for SC coincides with evaluating good practices and requirements and has a more robust basis than Neves et al. [60]. This last aspect represents an advantage, as the EMEM proposes an evaluation with an internal and external scope of the SC.

Zeinalnezhad et al. [61], proposes indicators to assess the performance of the implementation of health, safety, environment, and ergonomics management systems (HSEEMS), considers aspects of Malcolm Baldrige's award and the European Foundation for Quality Management (EFQM) for the determination of the eight criteria including leadership, strategy, risk analysis, people, resources, health, safety, environment, and ergonomics (HSEE) implementation, stakeholder effects, and key performance effects. The process of implementing or assessing the criteria is so far incomplete that the scope or strategy of the assessment is unknown. There is some overlap between the criteria used and the proposed model. However, the EMEM presents a more comprehensive assessment procedure and a management index for feedback and monitoring of the management process.

Finally, Rezvanizadeh et al. [62] propose an ergonomics management model for workstations consisting of 8 steps: 1) Performance of task analysis (TTA), 2) Identification of ergonomic risks, 3) Estimation of the ergonomic index, 4) Determination of control measures, 5) Evaluation of cost-benefit parameter, 6) Implementation of control measures, 7) Continuous monitoring and 8) Evaluation of the effectiveness of control measures. This model was designed to evaluate workstations and is considered an evaluation with a microergonomic approach. In contrast, the EMEM of SC was developed to adopt a macroergonomic approach due to its scope in evaluating the different links that make up the SC, which would allow its use in the various productive sectors. In addition, there are similarities between the eight steps of the model and the EMPr&Rq evaluated in the EMEM, as both emphasize the identification of risks and have an index, but this evaluates aspects of physical, mental, and environmental ergonomics through traditional ergonomic methods. In addition, they consider applying control measures, monitoring, and assessing the effectiveness of the implemented measures. However, the EMEM lacks a cost-benefit assessment.

Comments 2: The study references multiple theories and models (ISO 45001, PDCA, Sustainability pillars). How were these frameworks integrated to ensure consistency in the proposed model?

Response 2: Thank you for your question. As a response, ISO 45001 was chosen as the basis and structure for the ergonomics management system since it has proven clauses for occupational health and safety management. It provides good practices and requirements, which are adapted, as suggested by Rodríguez-Gámez et al. (2024), to the ergonomics management environment, and evaluated in the EMEM. On the other hand, the continuous improvement model provides the EMEM with a management scheme that facilitates its implementation. Its goal is to constantly manage ergonomics in the supply chain through compliance with the practices and requirements established in the EMEM. Finally, the social sustainability pillar frames the contribution of implementing this EMEM.

Comments 3: Given the complexity of sustainability in supply chains, how does your model account for trade-offs between economic efficiency and social sustainability?

Response 3: The EMEM focuses on evaluating the practices and requirements in the supply chain through the constructs and domains established by Rodríguez-Gámez et al. [46] to contribute to the social sustainability of the supply chain through an evaluation system that provides an index of EM. This contribution to social sustainability is associated with improving working conditions that impact workers' health. This has an economic impact on organizations, reducing costs associated with injuries, absenteeism, and staff turnover and increasing productivity. In addition, the EMEM, through the EMI, makes it possible to establish an action plan that considers the highest priority risks or problems to guide those responsible for implementing ergonomic improvement actions; this allows for a better allocation of available resources.

Comments 4: The study emphasizes the PDCA cycle and ISO 45001 for continuous improvement. How does the EMEM address the challenge of sustaining long-term compliance and improving ergonomic practices?

Response 4: The EMEM is based on the PDCA continuous improvement model and evaluates these aspects, as well as leadership and personnel participation, which are crucial and relevant elements for maintaining long-term compliance with ergonomics management practices and requirements. In addition, the EMEM is an iterative process of continuous improvement that potentially reduces risks, improves working conditions, reduces costs, and provides the basis for informed decision-making and improving ergonomic processes. This iterative evaluation process enables the organization or links to repeat the cycle as often as needed after implementing improvement actions to comply with ergonomics management practices and requirements. These improvement cycles are represented by the Ergonomics Management Index (EMI) at various execution levels, which allows for the quantification of progress or regression during each implementation cycle.

Comments 5: How does the EMEM facilitate the identification of specific risk factors that companies should prioritize?

Response 5: The identification is made through the results obtained for each EMI in its hierarchy, such as EMIFR, EMIConstrucs, EMIlinks, and EMISC. The results with the highest score are considered a priority. Furthermore, if any ergonomics management practices and requirements have not been implemented, they should be prioritized. The EMISC score can be used with the scale provided in the manuscript to determine the performance level.

Comments 6: What measures are in place within the EMEM to account for psychological and cognitive ergonomics and physical ergonomics?

Response 6: The EMEM, in its evaluation through the self-evaluation instrument (EMSI), was designed by Rodríguez-Gámez et al. (2024), considers and evaluates compliance with:

1. Are processes in place to identify and evaluate ergonomic risks?

2. External factors such as regulations, norms, laws, and professions are considered.

3. Workers' competence is developed to include their participation, knowledge, and skills necessary to identify ergonomic risks and hazards associated with their work.

4. The organization has established, implemented, and maintained procedures to eliminate hazards and reduce ergonomic risks. These practices and requirements are considered to include psychological, cognitive, and physical ergonomics.

Comments 7: Can you clarify whether the model's functional requirements (FRs) and design parameters (DPs) were validated against real-world ergonomic assessments?

Response 7: As a response, Rodríguez-Gámez et al. (2024) validated the relevance of the Good Practices and Requirements of Ergonomic Management (FRs) based on the experience of experts. This validation involved performing an exploratory factor analysis (EFA) followed by a confirmatory factor analysis (CFA) for the Plan, Do, Check, and Act constructs. As a result, the instrument was confirmed to be valid for all proposed constructs. The design parameters (DPs) were validated by implementing a case study, as the Ergonomics Management Self-Assessment Instrument (EMSI) provided an assessment item corresponding to each FR.

Comments 8: Was any external validation (e.g., independent auditors, third-party assessments) conducted to verify the accuracy of the EMEM implementation results?

Response 8: Thank you for your question. As a response, one of the EMEM implementations was conducted in the salt company's supply chain, which served as the case study for this research. In this company, the ergonomics management levels of three internal supply chains for the essential products were evaluated and compared subjectively by the safety manager and other collaborators. Additionally, the Ergonomic Management Indices (EMIs) results were analyzed to ensure that the EMEM provided accurate data that reflected the actual conditions within the company. This approach allowed us to gain a clear representation of the realities present in the evaluated supply chains.

Comments 9: Could this model be integrated into digital tools or software platforms for companies to adopt it easily?

Response 9: Thank you for your question. In our conclusion, we recommend that future research use this model as a foundation for software development in the digital transformation era. This approach will help implement the model and demonstrate the benefits of ergonomics in supply chains. We are already in the process of developing this project as future research.  

Comments 10: Have you considered integrating real-time ergonomic monitoring systems, such as wearable sensors or IoT-based tracking, into the model for continuous assessment?

Response 10: Thank you for your question. As a response, we have not considered integrating real-time ergonomic monitoring systems since part of the self-assessment (participant's perception) focuses on the percentage of compliance with the practices and requirements related to identification and assessment of ergonomic risks, implementation of controls to reduce risks, compliance with applicable laws and regulations, and continuous improvement of ergonomics management. We recommend performing this evaluation from an organizational ergonomic perspective during and after the continuous improvement cycle, with the required implementation and intervention in the company, or as an initial evaluation to define the action plan. However, we are developing software to facilitate the recording, assessment, and reporting.

Ergonomics Management Evaluation Model for Supply Chain: An Axiomatic Design Approach

2. Questions for General Evaluation

Reviewer’s Evaluation

Response and Revisions

Is the content succinctly described and contextualized with respect to previous and present theoretical background and empirical research (if applicable) on the topic?

Yes

Are the research design, questions, hypotheses, and methods clearly stated?

Can be improved

Since these were lacking, a research question and a hypothesis were posed. In addition, the method's description was improved to facilitate its understanding.

Are the arguments and discussion of findings coherent, balanced, and compelling?

Yes

For empirical research, are the results presented?

Can be improved

In general, we adhere to all the recommendations from the author. Specifically, we have made the following changes:

1.        We change the style and format of all equations in the manuscript.

2.        We check the consistency of capitalization throughout the manuscript and rewrite the necessary words to ensure consistency.

3.        We improve the style of all the Figures in the paper

4.        We actualize the list with all Abbreviations included in the paper

5.        We have included an outlook at the end of the conclusion.

These are detailed in the point-by-point response observations in the following section.

Is the article adequately referenced?

Yes

Are the conclusions thoroughly supported by the results presented in the article or referenced in secondary literature?

Yes

3. Point-by-point response to Comments and Suggestions for Authors

Comments 9: Line 91: “HFE” is the same as “HF/E” in Line 61? Make it consistent.

Response 9: Thanks for the observation. As a response, we use “HF/E” consistently in the paper.

Comments 10: Line 105: Should it be “OHSAS”?.

Response 10: We agree, we have modified the word OSHAS in line 105.

Comments 11: Line 129: Give an overview of the paper structure: “In Section XXX, …”.

Response 11: Thanks for your observation. As a response, we write a paragraph explaining the paper structure; you can see in line 137 

Comments 12: Line 188: The comma should be deleted, also in Line 204.

Response 12: We agree. We deleted the two commas.

Comments 13: Line 194: The ISO is defined as “International Organization for Standardization“.

Response 13: We agree. As a response, the definition of ISO was modified through the correct arrangement of words.

Comments 14: Figure 1: What do the numbers in brackets mean?....

Response 14: The numbers given in brackets refer to the clause numbers in ISO 45001:2018 occupational health and safety management systems. We put a note about the explanation in Figure 1

Comments 24: * Figure 3: Avoid the page break within the Figure. It is better to use an equation when it is not a real figure.

Response 24: We agree. Three equations changed Figure 3 to exemplify the three basic configurations concerning the independence of the FRs: uncoupled (see Equation 3), decoupled (see Equation 4), and coupled (see Equation 5).

Comments 25: * 3: Log should be written in normal (not-italic) math mode. And is normally the base two logarithm?.

Response 25: We agree, we modified the term “log” to the new Equations 6, 8, 9, and 32. These equations were 3, 5, 6, and 24. Additionally, we expressed logarithms in base two in these new equations.

Comments 26: * Line 369: pi should be written as in Eq. 4.

Response 26: We agree, we modified the (P_i). 

Comments 27: * 4: The words “common range” and “system range” should be written normally. 

Response 27: We agree. We changed the terms to a normal format for the new Equations 7 (before it was Equation 4) and 8 (before it was Equation 5).

Comments 28: Figure 6: Can be deleted. No added value to the text.

Response 28: We agree. We have deleted Figure 6.

Comments 29: * 6: “EMI”, “SR” and “CR” should be written in normal mode. Also the words in the following equations.

Response 29: We agree. As a response, we write the words in normal mode in Equation 9 (before it was Equation 6) and for all equations in the manuscript.

Comments 30: Line 468: What is “RD”?

Response 30: Thanks for the observation. As a response, it is an error; the correct term is DR. We revised and changed the term in the entire paper properly.

Comments 31: Line 474-478/ 480-481/ 483/ 485/ 487/ …: Improve the style. For example, use an enumeration with bullet points.

Response 31: Thanks for your comment. We agree. The explanation of sections 3.2, 3.3, and 3.4 was improved using an enumeration with bullet points.

Comments 32: Line 598: The style differs from Line 579.

Response 32: Thanks for your observation. We change the style of section 3.6 (before it was  line 598) to the same way as section 3.5

Comments 33: Line 603: Use Subsections 3.6.X for the phases I to V.

Response 33: Thanks for your observation. We used Subsections 3.6.X for the phases I to V.

Comments 34: Figures 16-19: better define the figures as equations.

Response 34: We agree. We change the four Figures by equations.

Comments 35: Figure 20: Increase the resolution or use a vector graphic. The quality is insufficient.

Response 35: We agree. We increase the resolution of Figure 20 using a vector graphic.

Comments 6: Response 25: “log” is not written in normal (not-italic) in Eq. 6

Response 6: We agree: As a response, we change "log" in eq.6.

Comments 7: Response 26: p_i should be written in Eq. 6 as in Eq. 7. Also, variables like n, i, x should be written in italic mode. But words, units, abbreviations, functions should be written in normal mode.

Response 7: We agree. We change pi in Eq. 6 and modify the variables in italic mode in the equations and the manuscript.

Comments 8: Response 31: Not easy to see due to the coloured changes. Better upload a clean version in the next revision.

Response 8: We agree; we upload a clean manuscript version for easier review and a PDF version of manuscript.