Revealing system variability in offshore service operations through systemic hazard analysis

Puisa, Romanas; Bolbot, Victor; Newman, Andrew; Vassalos, Dracos

doi:https://doi.org/10.5194/wes-6-273-2021

Articles | Volume 6, issue 1

https://doi.org/10.5194/wes-6-273-2021

© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Special issue:

Wind Energy Science Conference 2019

https://doi.org/10.5194/wes-6-273-2021

© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Articles | Volume 6, issue 1

Research article

|

10 Feb 2021

Research article |

| 10 Feb 2021

Revealing system variability in offshore service operations through systemic hazard analysis

Romanas Puisa, Victor Bolbot, Andrew Newman, and Dracos Vassalos

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Final revised paper (published on 10 Feb 2021)
Preprint (discussion started on 12 Feb 2020)

Interactive discussion

Status: closed

AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment

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- Supplement

RC1: 'Some technical notes on the manuscript', Anonymous Referee #1, 16 Apr 2020
- AC1: 'Response to Anonymous Referee #1, 16 Apr 2020', Romanas Puisa, 20 Apr 2020
RC2: 'Review of the manuscript', Anonymous Referee #2, 10 Jul 2020
- AC2: 'Response to Anonymous Referee #2, 24 August 2020', Romanas Puisa, 24 Aug 2020
RC3: 'Comments', Anonymous Referee #3, 27 Jul 2020
- AC3: 'Response to Anonymous Referee #3, 24 August 2020', Romanas Puisa, 24 Aug 2020

Peer-review completion

AR: Author's response | RR: Referee report | ED: Editor decision

AR by Romanas Puisa on behalf of the Authors (24 Aug 2020) Author's response Manuscript

ED: Referee Nomination & Report Request started (26 Aug 2020) by Michael Muskulus

RR by Anonymous Referee #3 (13 Sep 2020)

RR by Anonymous Referee #2 (08 Oct 2020)

Suggestions for revision or reasons for rejection

The original paper used hazard exposure (the number of scenarios that could lead to a hazard) to quantify the likelihood of the hazard. I criticized that because I can see no justification that all scenarios are equally likely to happen. The revised paper does not refer to hazard likelihoods, but instead, it defines the ‘system variability’ as the number of hazardous scenarios per operational state, divided by the total number of hazardous scenarios. The rationale is that the number of hazardous scenarios indicates how complex a system is, and thereby where uncontrolled variability is more likely, and therefore where resources should be added: “The results of the systemic hazard analysis can be used to locate where such uncontrolled variability is more likely—the likelihood arguably increases with the number of hazardous scenarios—and where resources and capabilities should be added to facilitate performance adjustments.” (line 377-379)
Thus, it seems that the ‘system variability’ is still used somehow as an indicator of the likelihood of the hazard.
However, rational allocation of resources should be made based on risks, considering the likelihood and consequences of hazardous events. The systemic analysis would provide valuable input for making such analysis, but I do not get why the defined system variability would give any useful information. For example, if a new safety system is added, would that decrease the number of scenarios leading to a hazard, or could the number actually increase, as the system will become more complex? (Maybe the new system could fail in two different ways, thus each existing scenario would lead to two scenarios when combined with the ways the new safety system could fail.)

I do believe that the authors have made an interesting and useful qualitative analysis, and they have done a big effort arguing for the rationale behind the ‘system variability’. Unfortunately, I do not find this quantitative measure useful. I suggest the authors to remove the part on the quantitative measure of 'system variability', and instead focus on how the results from the systemic analysis could be used as basis for an actual risk analysis (without actually making one).

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ED: Reconsider after major revisions (24 Oct 2020) by Michael Muskulus

AR by Romanas Puisa on behalf of the Authors (14 Nov 2020) Manuscript

ED: Referee Nomination & Report Request started (04 Dec 2020) by Michael Muskulus

RR by Anonymous Referee #3 (21 Dec 2020)

ED: Publish as is (06 Jan 2021) by Michael Muskulus

ED: Publish as is (11 Jan 2021) by Joachim Peinke (Chief editor)

AR by Romanas Puisa on behalf of the Authors (11 Jan 2021) Manuscript

Short summary

The paper proposes a quantitative, non-probabilistic metric for the preliminary comparison of safety of windfarm service operation vessels (SOV) in typical phases of operation. The metric is used as a conditional proxy for the incident likelihood, conditioned upon the presence of similar resources (manpower, time, skills, knowledge, information, etc.) for risk management across compared operational phases.