Nondestructive Testing	Home Page > Risk Based Inspection
		RISK BASED INSPECTION

Risk Based Inspection

A fundamental consideration for plant operators is what, where, when and how to inspect to achieve the balance of statutory compliance and assured integrity - at affordable cost. Too little, too late means higher risk and probability of failure - and failure is expensive in terms of lost production revenue and the consequential impact of damaged reputation. Too much too soon means excessive cost; particularly in terms of disruption and resultant lost production revenue. The need for inspection is obvious and the reasons manifold. Very often the need is obligatory based upon the need to demonstrate quality and integrity. Sometimes it is a sensible precautionary measure which helps mitigate risk and underwrite integrity.

When used pro-actively, as an integrated source of plant condition information, it is a powerful management tool which enables more effective commercial management of vital assets, facilitates cost efficient production and maintenance scheduling and mitigates the probability and impact of failure.

At the point of manufacture, fabrication or construction all components and assemblies requires inspection to ensure 'as made' quality compliance with the regulations pertaining to safe and reliable use. Once in service these same products need periodic assessment to ensure that they continue to be fit for safe and reliable purpose.

But not everything can be inspected 100% on a regular basis …….and not everything needs to be!

Those parts which are not critical can be tested less frequently - particularly those which are not exposed to conditions which are likely to incur serious problems, those which have minimal impact in terms of safety and productivity and those which are routinely serviceable or replaceable. More significantly, most defects are predictable in terms of their probable cause, nature, location and integrity impact.

This risk & probability based assessment approach helps determine what should be inspected, where the focus of attention should be and what to look for - but the question remains when and at what frequency should inspection be performed.

On the question of affordability a further consideration has to be made to establish the differential between getting it right and the consequential cost of getting it wrong. Exercising this judgement requires a good understanding of the factors affecting condition, actual condition and the probability and consequence of failure. NDT provides answers to these questions.

Risk Based Inspection (RBI) is term coined in the 1990's in an attempt to define a more systematic and predictive means of assessing and classifying the criticality of plant with respect to probability and impact of failure. The strategy is not restricted to safety and can embrace other criteria such as availability, priority and viability of production assets, as a precursor to more effective production scheduling and maintenance planning.

As an inspection service provider we firmly believe that NDT is an important asset management tool which, if used appropriately, can help reduce risk, increase awareness and improve confidence. We also believe that the improved awareness afforded by more meaningful information of plant condition can yield significant savings in terms of increased availability, reduced engineering costs and more cost effective shut down & maintenance scheduling.

Although we are not Plant Engineers we do have an extensive knowledge of material degradation mechanisms and defect types. By working closely with our clients, their engineering advisors and insurers, we are able to use RBI to focus on the task at hand and ensure that we apply the most appropriate techniques based upon an awareness of the factors and conditions which affect integrity. This approach also enables our clients to better appreciate the pros and cons of the various techniques available and the impact they may have on their schedules and their budgets.

- When to Inspect?
- Why shut down?
- Risk Based Inspection
- What to Inspect?
- What does it cost?
- Which Technique?

For further information on our RBI philosophy, contact Colin Mortimer