Prioritising Maintenance Work Orders in a Thermal Power Plant: A Multicriteria Model Application

Round 1

Reviewer 1 Report (Previous Reviewer 1)

I would like to thank the authors for providing a revised version of their work. I have some editorial and technical comments:

1. Abbreviations:

Some abbreviations used in the paper do not match the description. Maybe because they are taken from their Portuguese words. However, they can be confusing, example:

National Electric System Operator (ONS)

Thermoelectric Power Plant (UTE)

determination of the fundamental points (PVF)

Primary Elements of Evaluation (EPAs)

- Also, generally we use abbreviations if a phrase is repeated multiple times in a paper. In which case the abbreviation must be explained only the first time it appears in the paper. This seems to be not the case. Some abbreviations are not explained at all, some do not need to be abbreviated as they are not repeated, and some are expanded multiple times.

2. Run-on sentences

There are multiple cases of run-on sentences, which from own experience  I know it is very common in some languages. However, shorter sentences can be more professional and easier to understand. I provide just two examples:

"For the PCM (Maintenance Planning and Control), it becomes complex to decide only with the Engineering criteria, with the vision of the equipment only, which activity should be prioritised over another due to a diversity of areas, systems, equipment and their specificities and criticality concerning the process and the risks and impacts involved."

"According to the results of the judgment matrix of the MACBETH approach, the proposed ranking allowed the revision of the maintenance planning strategy that now uses the risk factor based on the confirmation that the weights and criteria are robust for its application, which is already bringing gains in practice to increase the plant's reliability."

3. Proofreading

The new submission shows significant improvement compared to the previous one. However, I feel there is more room for improvement. There are still some grammar errors and instances of capitalizing letters or using italic fonts unnecessarily. However, my main concern is how wordy the paper is. The paper could be written in more information-dense manner. Proofreading by a professional English-speaking editor is highly recommended.

4. Literature review 

Literature review has been improved since the last submission. What is still missing is the gap in research and comparison between the applied method and the previous work.

There are several cases of direct quoting in the paper which is unnecessary unless citing a definition. This could be replaced with rewording and summarizing of the main points of the articles.

5. Novelty

One main concern that the authors still need to address is the main novelty and contribution of the work compared to what is available.

What is missing in the previous works and what problem your approach is solving? MACBETH and multi-criteria methods have been used for maintenance of plants in the past (some links are listed here). What are you doing differently in your approach that could be on interest to the reader?

https://www.mdpi.com/1996-1073/14/12/3682

https://link.springer.com/article/10.1186/s12911-016-0282-7

https://www.sciencedirect.com/science/article/abs/pii/S0360544217306667

https://link.springer.com/article/10.1007/s41872-022-00206-2

https://www.taylorfrancis.com/chapters/edit/10.1201/b22494-1

https://www.pomsmeetings.org/ConfProceedings/065/Full%20Papers/Final%20Full%20Papers/065-1977.pdf

6. Redundant and too-general material

Parts of section 2 is too general and redundant. I feel that the evolution of maintenance practice can be discussed more briefly in one or two paragraphs. Providing a general history of maintenance does not seem to be the main contribution of the paper, but multiple paragraphs have been spent on it. Example:

"Maintenance activity has been employed since the beginning of civilisation, with the conservation of small objects and repair of tools used in daily activities. However, it was after the industrial revolution that maintenance started to be employed in industries, and since then, it has been developing faster and faster [7]."

In early industrial times, maintenance was seen as a necessary evil. However, as the industrial processes developed, their importance became clearer and more transparent. Thus, maintenance became an indispensable sector for the survival and growth of any company since its effects directly affect the environment, performance, and safety of industrial processes [8]."

7. Results

There are not so many results, discussion, and analysis are available.

Figure 4 and Table 2 seem  to be the only results presented in the paper and they are not discussed properly. I suggest adding more test cases, scenarios, and analysis. Also, comparison with other methods is necessary to show the efficacy and efficiency of the applied method.

8. Conclusion Discussion

Conclusion section only summarize the contributions of the paper. No new information should be presented in this section. I suggest breaking this section into two sections, Discussion and Conclusion. Keep the conclusion brief while analyzing the results and limitation in the discussion section.

- Moreover, where is the result of your sensitivity analysis? It is mentioned in the conclusion for the first time

"A sensitivity analysis was performed at the end of the method"

- I am not sure if the greyed out part of the conclusion is to be removed or not, but one sentence appears twice:

"According to the results of the judgment matrix of the MACBETH approach, the proposed ranking allowed the revision of the maintenance planning strategy that now uses the risk factor based on the confirmation that the weights and criteria are robust for its application, which is already bringing gains in practice to increase the plant's reliability."

Author Response

Dear reviewer, we would like to thank you for taking the time and effort to improve this article. The suggested revision is provided below.

Sincerely,

The authors

Unifor-Brazil

Author Response File: Author Response.pdf

Reviewer 2 Report (Previous Reviewer 2)

With respect to the previous version (that I rejected), the paper has been significantly improved, expecially in terms of English language and reduction of scholastic contents. This makes the scientific and innovative contents appear more clearly.

For these reasons, I think that the paper requires actually only some minor revisions before publication, that is:

- Figure 3 is hardly readable: please improve its quality.

- Sections 5 and 6 seem to be very short with respect to previous sections. Moreover, Conclusions, in my opinion, are too long, because they include comments that could be considered as a "discussion" of the results.

For this reason, I suggest to unify Sections 5 and 6 in only one section; it could also include the paragraph about the sensitivity analysis, that is actually in the Conclusions.

At the same time, the description of the results should be improved with more details: for example, a clear description of the figures and tables (including an exact explanation of the meaning of abscissa, ordinate, lines and columns), would be appreciable and useful for the clarity of the paper.

- pag. 16 lines 707 and 713: "table 1"? The results appear in a "table 2". Please check and correct.

Author Response

Dear reviewer, we would like to thank you for taking the time and effort to improve this article. The suggested revision is provided below.

Sincerely,

The authors

Unifor-Brazil

Author Response File: Author Response.pdf

Reviewer 3 Report (Previous Reviewer 4)

The authors have made the requested changes, so I now believe that this latest version of the manuscript is suitable for publication. 

Author Response

Dear reviewer, we would like to thank you for taking the time and effort to improve this article. 

Sincerely,

The authors

Unifor-Brazil

Round 2

Reviewer 1 Report (Previous Reviewer 1)

- References should be cited in the order they appear in the list. References 48 and 49 should be moved up.

- Abbreviations should be expanded only once, not multiple times.

- In many sentences, the subject of the sentence is not clear. Starting a sentence with a gerund, and not being clear on the subject of the sentence is not a good writing habit.

- Capital letters are used in many cases that were not necessary or appropriate.

- The reference list needs to be formatted according to the template in terms of bold, underlines, and indentation.

- Paper is still filled with many example of run-on sentences. Most sentence longer than two or three lines need to be simplified.

- Figure 1 is mentioned as a flowchart, while it s just different phases of the project. This figure is not a flowchart or algorithm the way it is worded. 

- In Figure 2, for a flowchart's start and stop steps, usually an oval shape is used.

- Figures 1-4 and Table 1 are from your previous publication. Please cite the reference with the correct format. 

Author Response

Dear reviewer, we would like to thank you for taking the time and effort to improve this article again. 

Author Response File: Author Response.pdf

This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.

Round 1

Reviewer 1 Report

1. The level of English in this paper is below poor. I am putting the first three sentences of the abstract as an example to show that almost every sentence in this article needs rewriting in terms of comprehension, grammar, capitalization, punctuation, formatting, etc. Proofreading by a native English editor is recommended.

"Maintenance is one of the activities that most grew and grew in the industrial environment. Its application stopped limiting only to small repair routines and started to become a sector key to planning a company's strategy. In the case of plants, thermoelectric Maintenance plays a crucial role, as they do not operate continuously but only when requested by the National Electric System Operator to complement the generation from sources renewables such as hydro, wind, solar, etc."

2. Pictures are not original and with very low quality.

3. The novelty of the work is very limited.

4. The literature review is not complete and rather outdated.

5. Formulas need to be presented more clearly.

Reviewer 2 Report

The paper aims to present the results of the application of a multiple criteria methodology, based on MACBETH approach, on a real industrial case, that is a thermal power plant, with the final goal of optimizing maintenance services for increasing global productivity and efficiency.

Although I consider the proposed topic quite adequate, I think that the objective of correctly presenting such topic is not reached at all.

Here the main points which motivate my opinion:

- unfortunately, the English used is highly inadequate. It is not just a question of perfecting the grammar: in most parts of the text, the content cannot be understood at all by the reader. Consequently, it is not possible to completely get the sense of the paper, even for a reviewer.

- the text is full of redundancy - sometimes with a scholastic tone - of theoretical concepts about maintenance and its role, but the potentially interesting parts are really just few ones (mainly in Chapters 4 and 5). 

- it is not possible to present a paper for an international journal where the bibliographic references are almost totally coming from local literature and mainly consisting in doctoral thesis, University courses or technical manuals. The number of "serious" scientifìc references, coming from international literature, is too low (maybe only 7 or 8 on the total of 49 titles). The paper seems to be written by students, which is not a defect, but the authors (or some of them) probably lack experience in writing a paper for a journal. The problem is that, at the end, the reader cannot understand exactly what the paper describes.

- despite the titles of the sub-paragraphs, there is no a good organization of the contents in the text, which is long, but lacking in presenting clearly how the research was organized from the beginning to the end. Even the part where the software is described (which should be one of the most interesting ones) seems more like the transcription of an operational manual or a school text.

- moreover, the paragraphs are not well-organized, their numbering is uncorrect. Figures are not all clearly readable and some of them present differences from the written text, probably due to both English translation and lack of attention.

- results are not clear and it is not clearly described how they was reached. Probably the uncorrect English has a big role in causing that, but I cannot propose major revisions on a text where the sense of the sentences is - very often - impossible to understand. Moreover, the scientific level of the paper is not sufficient, because - in my opinion - scholastic structure and content are dominant.

Reviewer 3 Report

The scope of the study is interesting. However, authors need to improve manuscript significantly to be ready for publication. Following comments may help to improve the manuscript.

Abstract is poorly written. Novelty is missing. The objectives are not clear. Authors should mention the findings of study in brief. What does ordering mean? 

Introduction needs improvement. Initial statements need support of references.  Continuity in sentences/paragraph is missing. "According to observation....." entire paragraph need to revised and inline with the objective of the study. 

Develop research questions and objectives seperately pointwise for better understanding of readers.

Literature review section is missing. Kindly develop it and discuss research gaps.

Section 2 can be merged with introduction section as sub-section. 

"Maintenance unplanned corrective, schematised in figure 02, ....." confusing statement. Please correct it.

What is the significance of Fig. 2

Further sections are not clear.

Where is Section 3?

Revised Section 4. Discuss MCDM approach in detail. Provide necessary support for difference techniques and why author selected Macbeth approach. Please refer: https://doi.org/10.1016/j.techfore.2021.121217

Explain details of experts panel discussion. Why only 10 professionals are considered for analysis?

For delphi approach, what sampling approach was followed? 

"the fundamental distinction between MACBETH and other methods multicriteria is that this demands only judgments qualitative on the affinity differences between the elements to generate option scores on each criterion, weighting them." - explain this statement with example.

Develop discussion section

Implications are missing. Provide practical implications

Conclusion should discuss limitations and future directions.

Add references from 2021 and 2022. 

Reviewer 4 Report

The authors propose a study of maintenance orders, which is a fairly unexplored topic when placed in relation to issues of sustainability and in line with the purposes stated in the Special Issue in which the article is hinged. However, for the paper to be suitable for publication, several important improvements are needed, which I briefly describe here. 

1. In section (1) Introduction, the authors should provide a more detailed overview of the state of the art and, most importantly, should relate the issue of maintenance orders to sustainability implications, referring to recent literature published in impact journals (including Sustainability). In addition, the reader is expected to know what is the innovative contribution of the study compared to current knowledge. Unfortunately, the authors have not highlighted gaps in the literature that their study is expected to fill, nor have they enunciated research questions to formulate a clear research objective. This part needs improvement.

2. After the introduction, the reader would expect a section on methodology, but it is missing in this manuscript. The authors should see to it that an independent section is created that demonstrates, citing recent literature, that the application of the multi-criteria model serves the purposes of their research.

3. Section (2) The Evolution of Maintenance, which is descriptive in nature, should be included in the introduction because it helps build the state of the art. I also urge the authors to pay more attention to the way they categorize the paragraphs in this section. After paragraph 2.2.6, inexplicably appears paragraph 3.1 Operation of a Coal Thermoelectric Power plant, followed by section 4.Support Multicriteria Decision Making which inexplicably includes paragraphs 2.4.3, 2.4.4 (methodological), followed by paragraph 4.1 Application Phase and so on, Thus set up this part of the manuscript is illegible and the authors cannot understand the rank and sequence of the different topics, moreover the completely random use of boldface in the headings, further complicates the reading.  

4.  Section  (5) Various criteria Methodology should be included in the section on methodological approach after the introduction.

5. Section 5.Various criteria Methodology should be included in the section on methodological approach after the introduction.

6. Finally, in the conclusion the authors do not stress the theoretical contribution made by their study and do not sufficiently emphasize the implications for practitioners.