Maintenance Strategies for Industrial Multi-Stage Machines: The Study of a Thermoforming Machine
Round 1
Reviewer 1 Report
Dear authors,
Overall impression:
The article is very interesting but there are many flaws in terms of a thorough preparation.
The first section is very broadly researched, but it needs more visible clarity. The case study in section two needs to be detailed further. In section three more clarity needs to be added, e.g.: optical clarity needs to be established, figures need to be improved and explained in more detail, sources need to be added and argumentation need to be improved. In section 4 it should be concluded having the specific character of “multi-stage” in mind. There should be added a comment on further research”.
Detailed remarks:
For the comment numbers (Comment No) please see attached PDF. Please comment on each comment number.
Comment No |
Comment |
1 |
Language expression |
2 |
"Conventional" not clear |
3 |
Not clear, what "first case" is |
4 |
Source(s) missing |
5 |
Is there a logical relation between "single-stage" and "first case"? |
6 |
Definition multi-stage unclear |
7 |
Example for multi-stage missing |
8 |
Orthographical mistake |
9 |
Language expression |
10 |
Language expression |
11 |
"Alternative" not clear. Relation to "multi-stage"? |
12 |
Refer to later definition of MTTR |
13 |
Language expression |
14 |
"Based on the above" not clear |
15 |
"Desing S3-RF" not clear. Typo? |
16 |
Language expression |
17 |
Layout change: DBT is styled like a sub title, but all the other approaches weren't styled like "DBT" -> create subchapters with enumerations? |
18 |
Blank space |
19 |
Strive for a clear optical structure: the maintenance strategies should be associated clearly with paragraphs |
20 |
Language expression |
21 |
Logical link: machine learning <-> security? |
22 |
Language expression |
23 |
"based on computational data" not clear |
24 |
"behavioural models" not clear |
25 |
"the real model" not clear |
26 |
Source [37] is not related to multi-stage |
27 |
EDT not explained in details |
28 |
Layout change: DBT is styled like a sub title, but all the other approaches weren't styled like "DBT" -> create subchapters with enumerations? |
29 |
Section 1 should be structured more clearly e.g. with subchapters |
30 |
The paragraph should be shifted to the section 2 where the setup is explained |
31 |
The specific character of "multi-stage" must be detailed and worked out more intensively |
32 |
Language expression |
33 |
Missing labels in Figure 1 / Bullet points must be found also in Figure 1 |
34 |
Missing scale in Figure 1 |
35 |
"4.3-7-10" not nice |
36 |
Missing consistency: ";" <-> "," |
37 |
Missing consistency: ";" <-> "," |
38 |
Language expression |
39 |
PLC: all abbreviations must be explained at first usage |
40 |
Missing consistency: Origin <-> Source |
41 |
Consistency/Not clear: consequence of its failure <-> "Failure" in Table 1 |
42 |
Consistency: usage of capital letter "Static"<->"static" |
43 |
Consistency: usage of blank space bevor "/" |
44 |
Orthographical mistake |
45 |
Consistency: usage of "."<->"," |
46 |
Not clear: "are one of many multi-stage machines" |
47 |
Put step numbers in flag symbols |
48 |
Consistency: "." used |
49 |
Language expression |
50 |
Shaft to be identified in Figure 1? |
51 |
Language expression |
52 |
Language expression |
53 |
Unclear: favourable resolution |
54 |
Source(s) missing |
55 |
Consistency: writing of Multi Stage Thermoforming Machine |
56 |
"the fixed value of MTTF" not clear |
57 |
Unclear: "several strategies" - more than 1 - why? |
58 |
Language expression |
59 |
Language expression |
60 |
Not clear: "market values" |
61 |
- |
62 |
Source(s) missing |
63 |
Not clear what "has its own time values" means. Is this related to line 221ff? |
64 |
Language expression |
65 |
Source(s) missing |
66 |
Top border line of Figure 3 missing |
67 |
"i" should be indexed in Figure 3 |
68 |
Consistency: usage of capital letter "Motor" |
69 |
Consistency: usage of capital letter "Cutter" |
70 |
See 55 |
71 |
"on the supply of components" is not clear |
72 |
"substituting the supply time …" is not clear |
73 |
Main message of Figure 3 is the difference between IPPM and PPM - this must be pointed out in more details |
74 |
Consistency: usage of capital letter "Efficiency"/"Availability" |
75 |
Highlight "Peristaltic pump" if this is really the only mentionable point of Table 3 |
76 |
Why pointing out only "Peristaltic pump" in Text for Table 3 |
77 |
Orthographical mistake |
78 |
Orthographical mistake |
79 |
see 68 |
80 |
see 69 |
81 |
"electronic components" and "mechanical components" from text are not found in Figure 4 |
82 |
Language expression |
83 |
Language expression |
84 |
Language expression |
85 |
Language expression |
86 |
Language expression |
87 |
Difference between "expected time" and "known from experience"? |
88 |
Orthographical mistake |
89 |
Language expression: expression = equation? |
90 |
Please improve figure 5 |
91 |
Where SA1…SA6 to be found in Figure 5? |
92 |
Language expression: Setup instead of conceptualisation? |
93 |
Consistency: usage of capital letter "Humidity" |
94 |
Consistency: usage of capital letter "Thermoformer" |
95 |
Not defined: WIKA |
96 |
Not defined: HGC |
97 |
Consistency: usage of "items" in Table 1<->"Components" in Table 4 |
98 |
Unclear: The adoption of this …" |
99 |
Language expression |
100 |
See 89 |
101 |
Not clear: "command and signalling" |
102 |
Brackets around "7 and 8"? |
103 |
"do not apply for this model" - why? |
104 |
"Where MTBFi is the …": not a full sentence |
105 |
MTTRi: please use index for "i" |
106 |
100 machine cycles: why? |
107 |
Language expression |
108 |
Difference R(t,i) in (9) and R_((t,i)) in text? |
109 |
What is Ofi_i? |
110 |
Language expression |
111 |
Language expression |
112 |
Blank space |
113 |
"its shutdown" not clear - language expression? |
114 |
"is evaluated": language expression |
115 |
"x" is for cross product in (10) |
116 |
Source(s) missing for "c" is 0.67 |
117 |
"may have" not clear |
118 |
Blank space |
119 |
"was used for all "j" sensors": why? |
120 |
SA1…SAn -> use index: SA1 |
121 |
San. -> why "."? |
122 |
Avoid these few words in new line (STEP2, STEP6, STEP8) |
123 |
Blank space |
124 |
Blank space |
125 |
costi -> blank before index in (11) |
126 |
Language expression |
127 |
Language expression |
128 |
"that very moment": not clear |
129 |
"coordinated manner": not clear |
130 |
Language expression |
131 |
proved to be efficient |
132 |
Why Item with capital letter? Consistency with item/component? |
133 |
Language expression |
134 |
See 90 |
135 |
Setup instead of conceptualisation? |
136 |
Language expression |
137 |
Language expression |
138 |
Language expression |
139 |
ACZ not defined, Z is index? |
140 |
Use Index for Sai |
141 |
Consistency: usage of capital letter "behaviour map"<->"pattern of behaviour" |
142 |
The Study has been developed by evaluating…: not clear |
143 |
EP / Acz |
144 |
AC.1 to AC.8: Why "."? |
145 |
Not clear: using the encoder assessment scale |
146 |
In short…: not clear |
147 |
Language expression |
148 |
Language expression |
149 |
Any learning: not clear |
150 |
"Proposed DBT" on next page |
151 |
"EP1000)." not nice in new line |
152 |
See 120 |
153 |
Use symbol for arrows |
154 |
Blank space |
155 |
Font in equations is italic style, why - (14)? |
156 |
Language expression: "is other than" - "is different from" |
157 |
Language expression: "as to whether" |
158 |
Language expression: "this is" |
159 |
Language expression: reflect |
160 |
measurement scale has been assessed: not clear |
161 |
Language expression: only thing |
162 |
…has its own relationship. Proof? |
163 |
See 97 |
164 |
Language expression: without fail |
165 |
failure? |
166 |
See 120 |
167 |
"Very precise": not clear |
168 |
See 55 |
169 |
Is there a column "DBT false" not visible? |
170 |
All the "1" in the table are not vertically aligned |
171 |
strategies have been tested: test conditions? |
172 |
Consistency with item/component? |
173 |
See 120 |
174 |
Typo: SA2 and SA3 with index or not, see 120 also |
175 |
See 120 |
176 |
Language expression: expression = equation? |
177 |
Top border line of Figure 7 missing |
178 |
Top border line of Figure 8 missing |
179 |
"Comparison" - "Comparative values": consistency |
180 |
What shall i see exactly in the two figures 7 & 8? Please describe in detail in text |
181 |
of Availability values? |
182 |
significance need to be proven. It is a statistical term. |
183 |
Not clear: Given the results |
184 |
Language expression: is interesting |
185 |
Language expression: "could be an avenue" |
186 |
See 120 |
187 |
Language expression: to do so |
188 |
dmax / dmin: use index |
189 |
Please come back to the specific character of "multi-stage" in this conclusion |
190 |
What is the further research? |
191 |
Consistency: second name in bibliographic data abbreviated? |
192 |
Blank space |
193 |
Full or abbreviated first names in bibliographic data? |
194 |
Blank space |
Best regards,
Reviewer
Comments for author File: Comments.pdf
Author Response
We have just finished the review of our paper (Manuscript ID: sensors-1399311) titled “Maintenance Strategies for Industrial Multi-Stage Machines: The study of a Thermoforming Machine”. We sincerely appreciate the suggestions of the reviewers. We have tried to comply all the comments, which have been used to improve the quality of the original manuscript.
Author Response File: Author Response.pdf
Reviewer 2 Report
The authors propose two new predictive maintenance strategies that allow for the dynamic calculation of mean-time-to-fail (MTTF) values by logging data from strategically placed sensors in order to increase efficiency and availability. The measurements are collected either in predefined intervals or during specific machine phases which are measured by a position sensing device (encoder).
The strategies are then applied to an existing industrial multi-stage thermoforming machine in order to measure efficiency and availability and to compare against existing preventative maintenance strategies that are based on static MTTF values.
The evaluation of the algorithms on an actual machine and the collection of real-world data is very desirable. However, since the data points are limited (due to the infrequent occurrence of actual failures) it is questioned whether they are sufficient to formulate conclusive results.
The main strong point of the paper are:
a) Novel approach by using analog and digital sensors to improve predictive maintenance
b) The idea presented by the authors is both important and practical
c) The paper is overall well structured
With respect to weaknesses,
a) Some comparison points in the conclusion section are not clear and need to be rephrased
b) More datapoints would be useful in order to draw concrete conclusions
c) The literature cited can be improved with more recent publications. For example, with respect to studies based on machine learning which make it possible to work securely and prevent threats in the cloud, the following article could be relevant.
Α. Short, HC. Leligou, E. Theocharis, “Execution of a Federated Learning process within a smart contract”, IEEE International Conference on Consumer Electronics, 2021, January 10-12, DOI: 10.1109/ICCE50685.2021.9427734
Author Response
We have just finished the review of our paper (Manuscript ID: sensors-1399311) titled “Maintenance Strategies for Industrial Multi-Stage Machines: The study of a Thermoforming Machine”. We sincerely appreciate the suggestions of the reviewers. We have tried to comply all the comments, which have been used to improve the quality of the original manuscript.
Author Response File: Author Response.pdf
Reviewer 3 Report
This paper compares the results of diverse maintenance strategies for multi-stage industrial manufacturing machines. The authors analyze a real case of a multi-stage thermoforming machine. Two methods based on preventive maintenance, Preventive Programming Maintenance (PPM) and Improve Preventive Programming Maintenance (IPPM), are compared with two new strategies based on predictive maintenance, namely Algorithm life optimization Programming (ALOP) and Digital Behaviour Twin (DBT). The authors need to state their goals with the resulting experiments clearly. This study may raise the interest of the research community dealing with industrial maintenance.
The manuscript's structure could be improved by introducing a new section to analyze the Related Work, making it clearer the scientific goal of the study. It would be helpful to learn the positive and negative aspects of the commented related work. The authors did that somehow, but I think it may be improved. A table containing a comparison would increase the quality of the review. The description of the adopted method is not clear enough. It is expected to receive details that make the research reproducible. In fact, a methodology section would be helpful before the case study section. The Results and Conclusion section also should contain enough information for leading other groups to reproduce the proposed approach. The discussion of the results is concise and well written, but the conclusion section should be improved before publication.
Author Response
We have just finished the review of our paper (Manuscript ID: sensors-1399311) titled “Maintenance Strategies for Industrial Multi-Stage Machines: The study of a Thermoforming Machine”. We sincerely appreciate the suggestions of the reviewers. We have tried to comply all the comments, which have been used to improve the quality of the original manuscript.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Dear authors,
thank you for the accurate revision of the initial article.
The following points were noticed in the revised document:
- L155 Typo „researche“
- L647 „for many“: Language expression
- L655 „Due to“: Language expression, “because”?
- L666 Index on dmax and dmin
- L674 Typo: increase
- L679 Sai -> index “i”
- L686 Typo „De“
Best regards,
Reviewer
Author Response
We have just finished the review of our paper (Manuscript ID: sensors-1399311) titled “Maintenance Strategies for Industrial Multi-Stage Machines: The study of a Thermoforming Machine”. We sincerely appreciate the suggestions of the reviewers. We have tried to comply all the comments, which have been used to improve the quality of the original manuscript.
Author Response File: Author Response.pdf