Most marine craft represent Systems of Systems (SoS) and are an ensemble of complex systems, which have the potential for an extraordinary amount of structural and technical complexity and improving survey practice and process.
Because of this, a SoS can be vulnerable to sudden catastrophic collapse because of small and insignificant partial functionality losses in one of the constituent systems.
System Thinking
Unanticipated failures find more potential and more pathways to their occurrence when interventions in SoS operations, standards or processes are conducted without enough insight or understanding and without consideration of the fundamental nature of the complexity of the System of Systems (SoS).
- Avoidance: is the prevention of a disruption. Avoidance goes beyond traditional system safety considerations (Madni and Jackson, 2009) in that it encompasses the anticipation of a mishap based on the ability to detect ‘drift’ towards system brittleness, a harbinger of potential accidents.
- Survival: is the ability of a system to resist destruction or incapacitation in the face of a disruption.
- Recovery: is the ability of a system to survive a major disturbance even with degraded performance
Given these definitions, one can argue that if avoidance is achieved, then the need for survival and recovery are indeed reduced. However, avoidance is achieved through intervention, namely detection and isolation of threats/errors/ failures, so as to avoid their propagation.
The marine surveyor is a key enabler of avoidance, by applying systems thinking, a marine surveyor would be better equipped to contribute to avoidance by understanding critical systems and seeking out critical faults ahead of time and ensure resolution preventing cascading failure of systems in the System of Systems.
Improving Practice and Process
Typically, there can be two main modes of operation for marine surveyors depending on whether their primary objectives are proactive or reactive.
Proactive role
- Aim to identify problems before they occur.
- They are generally responsible for assessing vessels before purchase or during routine checks. In case any flaw or damage is located, a potential mishap is averted. Hence, these surveyors are considered to be proactive as the attempt to avert problems or mishaps.
Reactive role
- Are called in after some incident has occurred.
- They assess the problem or damage to the vessel
Since they assess the vessel as reacting to some occurrence, they are referred to as reactive surveyors.
The survey process
To carry out a survey on a vessel a marine surveyor:
- Follows a standardised practice that they have developed
- Follows a standardised process that they have developed
- Use checklists to ensure coverage of all items to be inspected
How good are your processes & checklists?
The Theory of Active and Latent Failures was proposed by James Reason in his book, Human Error.[1] According to Reason, accidents within most complex systems caused by a breakdown or absence of safety barriers.The checks in our checklists create these safety barriers.
The Swiss Cheese model (figure 1) the model describes the chain of an accident opportunity as many little deviances or omitted checks that, by themselves, are small but if all those little ‘holes in the “Swiss Cheese” line up then an unforeseen problem or accident can occur.
The holes in the cheese slices represent individual weaknesses in individual parts of the system or process and are continually varying in size and position in all slices. The process fails when holes in all the slices momentarily align, permitting “a trajectory of accident opportunity”, so that a hazard passes through holes in all the defences (checks), which can lead to a problem or accident.
This Swiss Cheese Model is directly applicable to marine surveying in particular:
- the process and associated checklists used in marine surveying
- errors by the practitioner that can occur.
In the diagram (figure 2), as part of the survey process, we are carrying out inspections or checks which could alert us to the potential for a possible problem / accident. Used under the Creative Commons Attribution-Share Alike 4.0 International license. Figure 1: Swiss Cheese Model
From the diagram (figure 2) it is clear that Oversight / Accident Opportunity 1 would not be seen (caught) by our process and checklists.
It is also errors in the execution of the process and violations that could create the potential for a possible problem / accident which in the marine surveying discipline could include:
Errors which Include:
- Decision Errors: Goal-directed behaviour that proceed as intended, yet the plan proves inadequate
or inappropriate for the situation. These errors typically result from a lack of information, knowledge or experience.
- Skill-based Errors: These “doing” errors occur frequently during highly practiced activities and appear as attention failures, memory failures, or errors associated with the technique with which one performs a task.
- Perceptual Errors: Errors that occur during tasks that rely heavily on sensory information, which is obscured, ambiguous or degraded due to impoverished environmental conditions or diminished sensory system.
Violations which Include:
- Routine Violations: Often referred to as “bending the rules,” this type of violation tends to be habitual by nature, engaged in by others, and tolerated by supervisor and management.
- Exceptional Violations: Isolated departures from authority, neither typical of the individual nor condoned by management
- Skill-based Errors can occur as marine surveying is a broad field and not all surveyors have all the necessary skills or depth of skills.
- Routine Violations and Exceptional Violations: How many marine surveyors are guilty of skipping what they consider some less important checks because they are in a hurry to get the job done?
How many less experience surveyors make isolated departures from authority, which are not typical nor condoned by management?
Does a marine surveyors evaluate all his checklists in terms of coverage to ensure that the alignment of holes is the “Swiss Cheese” model is less likely to occur?
Have industry standards bodies encouraged comparison of checklists and validation of checklist coverage?
Checklists
As indicated, checklists are an essential tool for marine surveyors to ensure structure and comprehensive coverage of the craft being surveyed.
Bad checklists do not spell out every single check and are:
- Impractical
- Vague
- Imprecise
Consequently, bad checklists promote holes in the Swiss Cheese and creates opportunity for deviation.
Good checklists, on the other hand, are:
- To the point
- Precise
- Efficient
- Easy to use in the most difficult situations.
Deviations from the process or checklist
Skill-based Errors, Routine Violations and Exceptional Violations can cause deviation from the required practice which introduces us to the deviation spiral.
Normalisation of deviance is the gradual process through which unacceptable standards or practice become acceptable. The process of normalisation of deviance can be seen in the “Deviation Spiral” (figure 3) where you can see a deviation from the original normal causes a new normal which, again, can be deviated from, causing another normal. Each of these deviances need only be small but the gradual acceptance of each, and subsequent “getting away with it” teaches us that the deviance is acceptable – until a problem / accident occurs.
Good checklists prevent holes in the Swiss Cheese and provide clarity that limits opportunity for deviation particularly unintentional deviation.
The marine surveying discipline should increasingly apply a systems-thinking lens that allows us to:
- hone our abilities to understand parts
- see interconnections,
- ask “what-if” questions about possible future behaviours
- be creative and courageous about process and practice redesign.
The techniques covered in this article are actively and successfully used in other disciplines and I believe are just as applicable to our own discipline.
Article by Nick Parkyn