ALARP risks

Figure 8. An example of the roll function in time domain and ALARP risk evaluation criteria applied for the assessment of safety of a ship in damaged conditions.

An example of application of the ship performance data regarding the ship roll function in time domain and ALARP risk evaluation criteria for assessment of a ship safety in damage conditions is presented in Figure 8. The vertical axis in Figure 8 regards the angle of heel in degrees and the horizontal axis concerns the time in seconds. 

This system has proven to provide adequate levels of safety in the Gulf of Mexico and other similar areas where it is possible to abandon the location during a catastrophic event. In the North Sea where harsh environmental conditions exist, a different approach to safety has evolved which is based on developing a Safety Case and calculating an Individual Risk Rate (IRR) to show that the risk to any individual working in the facility is As Low As Reasonably Practicable (ALARP). 

A Safety Case is a narrative that literally makes the case that an adequate level of safety has been reached for an installation. It requires looking at all potential hazards which could lead to a loss of the installation, a loss of life, or a major pollution event. A risk analysis is performed on each hazard evaluating the probability of the event occurring and describing the magnitude of the consequences. A discussion is then given of the measure undertaken to lower the probability of occurrence or to mitigate the consequences and a case is made that the risk for the installation meets the ALARP safety criteria. 

For risks falling below the line, efforts might be made to further reduce the risks so that they are as low as reasonably practical (ALARP). In other words, activities with risks in the ALARP region are candidates for further risk reduction to the extent such risk reduction can be justified by the additional resources required to achieve it. Figure 4.1 implies that for Higher risk activities in the ALARP region (those closer to the intolerable level), it may be appropriate to expend, proportionately, more resources for risk reduction than for those with lower risks. At some point, the risks become... 

Figure 4.1 Presentation of risk tolerance levels and ALARP region (Ref. 46).

Where risks are higher that normally acceptable and all reasonable mitigation measures have been examined to find out value and practicality, the principal of risk as low as reasonably practical applies. Where the available risk protection measures have been exhausted and the risk level is still higher that the accepted numerical value, the risk would be considered "As Low As Reasonably Practical" (ALARP). 

The regulatory environment is changing in Victoria with introduction from March 2000 of the Major Hazard Facilities Regulations, based on the Seveso II Directives. These are expected to flow on to the other states considered in this chapter. The key requirement of these regulations is the preparation of a Safety Case, which must demonstrate, among other requirements, that the risk from the new plant has been reduced to as low as is reasonably practicable - ALARP . The plants will incorporate a number of design features intended to reduce the risk from the facilities and demonstrate compliance with this criterion. 

The ALARP or tolerability region (risk Is undertaken only if a benefit is desired)... 

Applied is the ALARP-principle—risk should be as low as reasonably possible. 

In a tolerable situation the risks need to be reduced or handled in some other way within the limits of reasonable resource investments (ALARP, including best practice).6... 

For the sake of analysis the worst case conditions are usually analyzed for cost benefit decisions. In cases where the cost for any proposed recommendation is near or exceeds the potential remediation costs after the potential incident, the risk may be termed as low as reasonably practical (ALARP). 

ALARP (As Low As Reasonably Practical) The principle that no industrial activity is entirely free from risk and that it is never possible to be sure that every eventuality has been covered by safety precautions, but that there would be a gross disproportion between the cost in (money,time, or trouble) of additional preventive or protective measures, and the reduction in risk in order to achieve such low risks. 

Once the level of concern is understood, the FMEA team needs to appraise its likelihood. Remote and rare events may be acceptable without further action. The term ALARP is often used for such events it means reduce risk as low as is reasonably practical. Higher likelihood hazards will demand more attention, as indicated in Figure 8.10. The acceptance of a hazard without control needs to be justified. It is important to note that the FDA does not include likelihood in its guidance... 

It is rarely possible to completely mitigate a risk other than by somehow taking action to avoid the associated hazard in the first place. Instead, risks need to be reduced so that they become As Low As Reasonably Practical (ALARP). Remedial project actions should be specifically documented — this is sometimes referred to as the Safety Case. Remedial actions may employ hazard avoidance strategies, introduce hazard tolerant design feamres, or apply specihc project management controls, or a combination. Further information on risk management for medical devices can be found in ISO 14971. ... 

On this basis the concept of so far as is reasonably practicable (SFAIRP) was bom and subsequently enshrined in the 1974 UK Health and Safety at Work Act. SFAIRP, whilst a significant step forward, fails however to precisely acknowledge the notion of risk and its relationship to practicability. As such the slightly modified term as low as reasonably practicable (ALARP) has been widely adopted in the UK and some other countries as the basis for risk acceptability. The ALARP principle can be defined as that level of risk which can be further lowered only by an increment in resource expeuditure that is disproportionate in relation to the resulting decrement of risk [2],... 

The notion of ALARP is simple yet fundamental. Firstly it acknowledges that there is a difference between clinical risk being as low as possible and what can realistically be achieved. This important principle brings acceptance that organisations do not have an infinite amount of money, time and effort and that there are practical and technical boundaries on how far, from a safety perspective, one can go to reduce risk. In fact one could argue that to continue to reduce risk beyond what is reasonably practicable becomes an inappropriate use of resources and ultimately of little benefit. 

Finally ALARP introdnces a basis for justifying risks, to make a case for them being present but tolerable. To justify something in this way reqnires carefnl analysis and logic set out as an evidence-based argument. The vehicle for this jnstifica-tion is a document known as a safety case. 

Critics of ALARP often subscribe to the notion of minimum risk (rather than what is practicable) but this too has its shortcomings. Even if one accepts that risk... 

Note that there is no real concept of temporary ALARP , one cannot accept a non-ALARP solution whilst a permanent ALARP alternative is sought. A particular control may offer a temporary fix but the resulting risk is either acceptable or not at a given point in time. 

At this point it is worth mentioning how the ALARP approach to risk acceptability changes markedly when it comes to medical devices. For example. International Standard ISO 14971 [10] affords manufacturers the ability to justify risks on an ALARP basis. The European Commission Medical Device Directive (MDD) [11] cites ISO 14971 as a Harmonised Standard however the directive contains a number of Essential Requirements on risk acceptability which appear to conflict with ISO 14971. 

The notion of reducing risk to as low as reasonably practicable or ALARP has been widely adopted in some countries. This measure creates the necessarily flexibility to allow the justification of residual risk using a safety case. 

The majority of hazards will not be issues and will not typically benefit from routine weekly review by the project team. Hazards can, in the main, be seen as entities sitting in the background characterising the risk in the event than an incident was to occur. Their purpose is to focus and prioritise the development of controls during the CRM analysis and to demonstrate the practical measures that have been put in place to reduce the clinical risk to ALARP. In contrast, issues are problems which require active management - they need someone to take ownership and run with the task of fixing them. 

Occasionally one is faced with the scenario where the clinical risk associated with a hazard is unacceptable (i.e. where achievement of ALARP has failed). In this case it can be useful to promote the hazard to an issue. In this way the problem is ready to be picked up by the project team and be escalated accordingly. 

Risk acceptance criteria can be defined relative to the risk matrix. The as-low-as-reasonably practicable (ALARP) approach may be chosen, defining three risk levels [4] ... 

There are various definitions of asset integrity, but broadly, it can be defined as follows an asset has integrity when it performs as intended, is being operated as intended, and the risk of a failure occurring, which would endanger the safety of personnel, the environment, or the asset s value, is tolerable and has been reduced to as low as reasonably practicable (ALARP). 

Some risk analysts use the term as low as reasonably practical (ALARP) for setting a value for acceptable risk. The basic idea behind this concept is that risk should be reduced to a level that is as low as possible without requiring excessive investment. Boundaries of risk that are definitely acceptable or definitely not acceptable are established as shown in Figure 1.16, which is an FN curve family. Between those boundaries, a balance between risk and benefit must be established. If a facility proposes to take a high level of risk, then the resulting benefit must be very high. 

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