Situation Assessment—An Essential Functionality for Resilient Navigation Systems

Round 1

Reviewer 1 Report

I welcome this paper as a needed effort to tie together resilience, navigation and situation awareness. There are major shortcomings, however, in this conceptual exercice. First and foremost, you the authors acknowledge the importance of "anticipation" within the concept of situation awareness but not as a critical component of resilience. Please check, for instance "Resilience Engineering : Concepts and Precepts" by Hollnagel et al. from 2006. "This definitive new book explores this groundbreaking new development in safety and risk management, where 'success' is based on the ability of organizations, groups and individuals to anticipate the changing shape of risk before failures and harm occur.", is said within the abstract directly. In the existing literature anticipation within ship navigation has been explored at least by Wahlström et al. on paper called "Perspective-Taking in Anticipatory Maritime Navigation – Implications for Developing Autonomous Ships" (2019, Compit -conference). In more practical sense, it is so that good navigators anticipate the maritime traffic situation comprehensively by considering the future manouvers of the other ships in view of the other ships' aims, capabilities, communications, weather, and such. The aim in this anticipatory navigation is to reduce risk by creating space between ships, just in case something might go wrong.

You might also reconsider the divide between "technological system (without human in the loop)" and "socio-technical system (with human in the loop)". In fact, there is no technology separate from the human intervention - all technology, which is in use, needs human intervention and serves human needs. But this is up to you.

The writing style could be less technical, but please check the journal style nevertheless. Why write something like: "e.g. in [4-6], as well as abilities of socio-technical entities to sustain the functioning, e.g.in [7-9]" rather than explaining the issues as they are. Please communicate to the reader like one human to another.

The description of bridge personnel bemuses me. You write "Even though most recently delivered modern ships are equipped far above the required technical standards providing high level of automation, there are human operators, i.e. the officers of the watch (OOW) on duty on the ship’s navigational bridge." Of course there are human operators – you could open up this a bit, i.e., what kind of human operators there are. You have written about navigational tools extensively but very little about the bridge personnel, their tasks, responsibilities, etc. Besides, you seem to imply that high level of automation is usual within the maritime field. To the best of my understanding, the ships are commonly very old and the maritime field actually suffers from the lack of technology investments. Please mind that the biggest sailing nations are the Philippines, India and Nigeria – perhaps the authors do not come from these countries so the point of view might be unusual in emphasizing the high level of automation.

You end by saying that “All of the papers (including this) make clear that the consideration of single factors is insufficient to achieve resilience. Rather, it is more necessary to model, coordinate and adjust the interactions within ship’s navigation system on socio-technical level.” In contrast to this, resilient and safe navigation does not manifest within ships only but also between ships as ships negotiate one with another and consider each other. One good case you could look at is the Helge Ingstad case where the crew made mistakes in reading the traffic and in communications as well. The overreliance to AIS (that was in passive mode on Helge Ingstad) was the mistake made by the other ship’s pilot and VTS. In other words, traffic-level consideration is important in explaining Helge Ingstad case. “Within ship” analysis, recommended by you, is not sufficient: both ships made mistakes and mistakes were made in ship-to-ship interaction. You may either recognize this limitation or include traffic-level analysis within your paper.

Overall, I recommend more consideration to bridge personnel (for more user and socio on socio-technical) and between-ships/traffic-level considerations for including anticipation as a source of resilience. As such, the paper seems very much technology-focused and therefore insufficient in considering “resilience”, “socio-technical” and “situation awareness”.

Author Response

The answers have been presented in the attachment. 

Author Response File: Author Response.pdf

Reviewer 2 Report

The sections up to and including 2.3 are a good account of the background material on which the work is, and can properly, be built.

Line 87 includes the word 'unintended' .. threats. I think the authors mean 'unanticipated' - i.e. a threat kind or magnitude not anticipated specifically by the system designer/builder.

 

Section 3.1 takes up the issue of redundancy. In Jackson's work two classes of redundancy were identified: 'physical redundancy' (which Jackson refers to parallel redundant instances of directly equivalent means) and 'functional redundancy' (which Jackson uses to refer to a different method of achieving the same outcome being available). This distinction is likely to be useful here. The analysis which has been done follows the traditional reliability analysis of probability of operation. This approach limits the system under analysis to the technology of the navigation system but does not address the question of what happens in the socio-technical system (also discussed in the paper).

To address the socio-technical system approaches could be used to 'functional redundancy' such as the use of sextant and mechanical clock (competency required of RN officers to overcome the navigation outage that could be cause by nuclear induced EMP) - means to provide the outcome by independent means not subject to risk of common mode failure.

The idea in section 3.2 is important because it is a fat of life that technology is subject to failure. Therefore in the analysis of the system it is essential to consider how the system would operate in the event of any equipment item failing. This would identify how the users in the socio-technical system level would be able to achieve their intention through what is left of the system.

In line 329 you have interpreted 'drift correction' in relation to making corrections for multi-path propagation challenges. Jackson's interpretation of 'drift correction' includes this, but also, in the light of your case study of collision of Bulker and Ferry would interpret 'drift' as beginning when the course of one changed, putting the two into in imminent collision danger. 'Drift correction' would then do something to correct (or at least warn the human operators to take corrective action) - i.e. either an alarm notifying them of the danger and the source of the danger, or even automatically steering to avoid the danger (such systems are used in civil aviation).

In summary, I find the background material to be fairly well presented, although some updating of this section with specific discussion of principles which you later use in your case study would be useful.

I am interested to see the application of these ideas to the case study subject matter, which is a challenge area which engages with the characteristics of problems which Jackson's work was stimulated by. His background was civil aviation. I have the sense that the case is a proper place to apply the principles approach of Jackson, so the broad approach to your work seems appropriate to me.

The problem I find is that the discussion in the paper is not convincing t me as an application of the principles to the case. My suggestion on this matter would be to use the findings of official reports about he collision, which it seems you have already used to describe the event, and then to look tot he conclusions and recommendations part of that report, as well as modelling the socio-technical system implemented in the case (what equipment was in place and modelling how that interacted with the human aspect of the system to generate the outcomes observed.

The authors could relate the recommendations in the report with the set of principles Jackson has described AND also use the set of principles to propose and model the effect of, potential interventions.

Overall, I believe there is merit in the work and I would like to see the work improved.

Author Response

All of the reviewer comments have been taken into consideration. Paper has been improved in the way the reviewer suggested. Track changes are shown in the presented material. 

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

I find that the exchange with the authors has been mutually enriching and welcome the minor changes to the paper. In my personal view, it is good to point out mistakes made within the reviewer's assesments (here referring views regarding to the ages of the ships). I will accept the paper as such. However, I would note that any increase in the easiness in the reading experience would also increase the impact of your paper. In practical sense, I would open up the acronym MED within the conclusion part because many readers skip directly to the conclusions. Furthermore, I would crystallize a simple take-away message (or few) within the conclusions part as much as possible. You may ask yourself, for instance, “what should a marine engineer learn from this paper for achieving better ship design?”, and write some conclusions based on how you address that question. This is to say that the editor should provide the opportunity to make minor changes still although these should not be required.

Reviewer 2 Report

I am content with the changes made.