Human–Machine Systems Reliability: A Series–Parallel Approach for Evaluation and Improvement in the Field of Machine Tools

Round 1

Reviewer 1 Report

Complex machine workshops generate high scrap rates causing non-compliance with timely de-livery, and high production costs. And because they are in a serial and parallel configuration, then causes of failures and their detailed analysis are not well documented.

 

The authors in their pr-posed reliability methodology determine the reliability of the whole system by first evaluating the reliability of predefined component-subsystem relationships, and subsystems by themselves, and second by integrating their reliability indices to determine the reliability of the whole complex system.

 

They  propose a strategy to improve and to monitor the system peformance, includiong  four stages: a) structuring of the production system, b) definition, analysis, and modeling of the man-machine system, c) selection and adaptation of the evaluation model and d) system improvement proposal. These stages include the series and parallel systems approach, reliability tools, expert interviews, cluster, and root cause analysis.

 

For the statistical series-parallel model the source of the components that affected the reliability, were classified as mechanical or human error. Therefore, those classified as mechanical were analyzed based on the Weibull distribution, and those classified as human error were analyzed by using the exponential distribution.

 

The study is interesting.

Here are some improvement suggestions that need to be activated in order to accept the paper:

 

1. It need to be rearranged according to the standards. See for example the part "……… .Thus, in our pro- 23 posed reliability methodology we determine the reliability of the whole system by first evaluating 24 the reliability of predefined component-subsystem relationships, and subsystems by themselves, 25 and second by integrating their reliability indices to determine the reliability of the whole complex 26 system. Also, we propose a strategy to improve and to monitor the system performance, it includes 27 four stages: a) structuring of the production system, b) definition, analysis, and modeling of the 28 man-machine system, c) selection and adaptation of the evaluation model and d) system improve- 29 ment proposal. These stages include the series and parallel systems approach, reliability tools, ex-30 pert interviews, cluster, and root cause analysis. " It is not effective. Rearrange the abstrct according to intro, purpose, methods, results and conclusions.
2. In my opinion the methods and the results are mixed. This makes reading difficult. Authors need to answer the question "What is their study product / outcome?" So they have to rearrange the sections accordingly.
3. The discussion is short and there is no comparison with other studies.
4. Conclusions lack future prospects.

 

 

 

Minor points

5. Check figures, tables. They sometimes need improvements
6. Check if the text style always respect the MDPI standards

Author Response

The authors are grateful for the comments made to our manuscript, we consider the contributions of the reviewers to be very valuable and therefore we consider them in this new submission by responding to the comments specifically one by one, according to the attached document.

Author Response File: Author Response.pdf

Reviewer 2 Report

The paper presents a study of man-machine system by considering it as simple series and parallel configuration. Other than that, it is unclear what is new and significant research contribution and the study is rather basic.

For general production system, quality control methods such as control charts are widely used and how is this complement that or can be used with it? Monitoring time-between-events is an approach that could be used and it is effective.

Of course, most such systems are repairable, and there are plenty of research on repairable system and maintenance optimization. The authors should provide more and broader discussion as the methods are rather standard and the novelty is also not high.

As exponential distribution is a special case of Weibull, and it is not realistic for aging systems in reliability, comparing two is not needed. There are plenty of research done on that and a couple of references should be sufficient.

In fact, a more thorough literature search should be done, and recent and related works should be discussed.

Author Response

The authors are grateful for the comments made to our manuscript, we consider the contributions of the reviewers to be very valuable and therefore we consider them in this new submission by responding to the comments specifically one by one, according to the attached document.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

The manuscript improved a lot.

In my opinion it can be accepted

Reviewer 2 Report

This version can be accepted for publication.