RBI: A short history and justification

By Greg Alvarado, Chief Editor at Inspectioneering. May 20, 2013

Anyone who knows me knows that Risk Based Inspection (RBI), and Risk Management, are a passion of mine, so my next few posts will feature these topics. These are not all-inclusive, but has dozens of articles and you can join our LinkedIn Group for more.

Let me give start with a bit of historical perspective on where RBI came from. In the “old days” inspection programs were designed as a “hit or miss” activity. In general, during continuous run operations, we inspected pressure vessels and piping every 3 years. In batch run operations, we often inspected more often (especially for fragile equipment, i.e., glass lined, rubber lined equipment, etc. Equipment requiring corrosion control due to extremely high corrosion rates where substrate exposure to the process media would lead to quick leaks/failure), and hopefully found a potential problem before it resulted in a leak, failure, or worse.

The next stage of inspection program evolution was condition based monitoring. At this stage, we were calculating corrosion rates and thinking about damage progression, damage morphology, etc. This was better than before, but consequences of failure were not yet factored into the decision making process. Condition based monitoring was followed by RBI.

One of the primary advantages of a well implemented RBI program is that the following key question is answered: “How much confidence do I need to have in what I believe to be the condition of the equipment?” Relative risk values and other triggers can/will tell you when more information is needed, i.e. when the current or future level of uncertainty is acceptable or unacceptable. The answers should be evident and the risk drivers clearly identifiable. How accurate do you need to be about what you believe to be the condition of the equipment? How much uncertainty is acceptable?

Relative risk can dictate this (more about that in a coming post) as well as the other elements of the relative risk equation acting as triggers (e.g. damage factors, a sub-factor of the Probability of Failure in the API Recommended Practice 581 RBI methodology). The owner-operators’ strategy for managing equipment reliability, safety, and integrity would dictate how the triggers are used. Other defined criteria, such as health and safety consequences, financial consequences, environmental impact, and inherent risks should be considered as appropriate, as in keeping with your company strategies, regulatory, and insurer requirements.

That is why it is important, prior to beginning a program, for any organization considering RBI implementation to first understand its reason for utilizing RBI for Risk Management. As Stephen Covey stated: “Begin with the end in mind.” It is important that we ask ourselves, “Why do we inspect equipment in oil and gas producing, refining, petrochemical, chemical, pipelines, mid-stream gas and terminals facilities?” There are many reasons. Consider these examples:

  1. Metal loss can signal a potential effect in contamination of product purity, e.g. unwanted Fe ions and/or rust may contaminate the product.
  2. Regulators/regulations require it.
  3. Insurers require it.
  4. And most commonly, to “fine tune” the reliability prediction. In other words, to confirm the degradation rate so actions can be taken to insure, as best we can, that negative events are avoided and that reliability and availability targets are achieved.

Your reasons will help dictate your motives for beginning a program. These motives are key to direction, consistency, trust, sustainability, team cohesion, and overall success of RBI. Some sample motives include ability to:

  1. Better focus resources, both staff and monetary.
  2. Identify areas of vulnerability within an environment in a constant state of flux.
  3. Better manage equipment reliability with a limited budget.
  4. Remove equipment from the TAR list.
  5. Find justification to perform on-stream inspections instead of internal inspections.
  6. Optimally manage risks.

I have to emphasize a point here: RBI should never be utilized as a means to cut corners or solely to reduce cost. Points such as those exemplified by bullets 4 and 5 should not be the primary objectives of implementing RBI but rather are possible results of a responsibly planned and run risk management program.

Most basically, we use RBI (which costs money, takes time, and incurs risks of its own) to obtain information to “fine tune” the reliability prediction. Why? We get this additional information for health and safety, business, environmental reasons, so we don’t incur a leak that will shut the unit down or that could lead to a catastrophic event, potentially injuring people, damaging the environment, and to optimize total cost of ownership for our equipment. When we need to, we are collecting more data to know, to an “appropriate” level of accuracy, the true damage state of the equipment. This empowers us to manage equipment integrity better than we have in the past.

In next week’s blog, I’ll be defining risk and go more into RBI. Stay connected in the meantime with our email newsletter, the Inspectioneering Turnaround.

Comments and Discussion

Posted by Arthur Jensen on May 20, 2013
Greg - This is a very good summary of not only... Log in or register to read the rest of this comment.

(Inspectioneering) Posted by Greg Alvarado on May 21, 2013
Thanks Art, I am glad to see that this... Log in or register to read the rest of this comment.

Posted by [Removed] on May 23, 2013
Hello Greg,rnthank you for that short... Log in or register to read the rest of this comment.

Posted by (REMOVED) on July 25, 2013
Greg, I was so bold and copied the motives onto... Log in or register to read the rest of this comment.

(Inspectioneering) Posted by Greg Alvarado on July 26, 2013
Thanks Christos. I have learned the hard way,... Log in or register to read the rest of this comment.

Posted by Marcelino Naranjo on November 8, 2020
What is TAR? Log in or register to read the rest of this comment.

(Inspectioneering) Posted by Greg Alvarado on November 9, 2020
Turnaround. Log in or register to read the rest of this comment.

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