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What is Asset Integrity Management (AIM)?
In short, AIM can be defined as 'Life cycle control of failures'
In detail, AIM can be defined as a continuous process applied throughout design, construction, maintenance and operations to ensure assets are managed safely & cost effectively to meet the corporate acceptance criteria on the safety, environmental, business interruption and reputational risks.
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How to ensure assets meet corporate criteria cost-effectively?
This is possible only by utilizing proper methodologies to risk rank the assets and devise inspection & maintenance plans that would control risk & expenditures. Risk can be quantified and thereby controlled.
What is Risk?
Risk is the combination of probability of some event occurring and the consequences (usually undesirable) associated with that event.
In mathematical terms, Risk can be calculated by
Risk = Probability x Consequence
What is ALARP?
ALARP is an acronym for 'As Low As Reasonably Practical', which is a concept of minimization that postulates that attributes such as risk can only be reduced to a certain minimum under current technology and with reasonable cost.
Concept of ALARP in process sectors has three regions of Risk level viz. 1) Intolerable region 2) The ALARP or Tolerable region 3) Broadly acceptable region. The concept of ALARP is illustrated in the figure below with numbers for example only.
What is RBI?
RBI is an acronym for 'Risk Based Inspection' as per API RP 580 & 581. RBI defines the individual risk of operating equipment as a combination of probability of failure and consequence of failure and thereby helps to develop inspection programs that would specify 'what? where? & when?' to inspect.
What is RCM?
RCM is an acronym for 'Reliability Centered Maintenance' as per SAE JA1011.
RCM can be defined as 'a systematic risk-based approach to create an accurate, well targeted and optimized maintenance package that aims at achieving optimum reliability for a facility'.
SAE JA 1011 defines RCM as 'a specific process used to identify the policies which must be implemented to manage the failure modes which could cause the functional failure of any physical asset in a given operating context'.
What are SIL/SIF/SIS?
SIL is an acronym for 'Safety Integrity Level' as per IEC61508 addressing the integrity levels of safety instrumented functions & systems. SIL is the discrete level for specifying the safety integrity requirements of the safety functions where SIL4 has the highest level of safety integrity and SIL1 has the lowest. Safety instrumented functions (SIF) are termed as 'Electrical/Electronic and Programmable Electronic Systems (PES)' in IEC61508, which are the most widely used methods for protecting against process related hazards. In the figure SIF is shown to contain an initiator, logic controller and a field device. The control valve circuit shown is not a SIF. A SIF protects against a single hazard but a Safety Instrumented System (SIS) implements one or more SIFs.
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How do we get the asset integrity strategies for an asset during operational phase?
Using the best industry proven methodologies such as RBI, RCM and SIL, AIM strategies can be developed to manage an operating asset within the corporate acceptance criteria. Figure given below explains the process.
Why studies such as RBI, RCM, SIL are required for a process facility?
The reasons are
- To meet the regulatory requirements (this varies between countries).
- To meet the general inspection & maintenance challenge of maintaining optimum plant availability at lowest cost possible without compromising safety, environmental and business targets. This is possible only with strategies developed through systematic risk based approach.
- To increase reliability & availability of equipment / systems thereby the production.
- Benefit realization - Benefit realization has been proven with many studies based on direct man-cost reduction as well as indirect benefits of uptime and increased production. Figure briefs on the benefits of RCM.
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