This recommended pipeline risk assessment methodology is similar to SRA (Structural Reliability Analyses) and LSD (Limit State Design) or LRFD (Load and Resistance Factor Design). This is coincidental, since the methodology was developed independently from these techniques. However, despite the similarities, there are key differences. Similarities include: Focus on engineering principles rather than incident history Accommodates […]
Results for Uncertainty
Myth Busting—I don’t have enough data (Part 2)
In the first part of this discussion, we hopefully dispelled some myths about low data availability. We discussed how reasoning is used to generate data and how many useful pieces of risk insight emerge from even simple pieces of knowledge. We also contrasted a statistical approach to risk assessment with a physics based approach. The […]
Pipeline Risk Assessment—Myth Busting Part 1
In the first installment of this column, we introduced the concept of pipeline risk assessment Essential Elements. This is a list of ingredients that arguably must be included in any pipeline risk assessment. In this installment, let’s examine “I can’t do good RA because I don’t have enough data.” There are at least two aspects […]
Pipeline Risk Assessment—Controlling the Bias
In the first installment of this column, we introduced the concept of pipeline risk assessment Essential Elements. This is a list of ingredients that arguably must be included in any pipeline risk assessment. Last time, we covered one of these essential elements—the need for measurements. This time, we address another essential element, closely related to […]
It sounds like you have methods that very accurately predict failure potential. Is this true?
Unfortunately, no. While the new modelling approaches are powerful and the best we’ve ever had, there is still huge uncertainty. We are unable to accurately predict failures on specific pipe segments except in extreme cases. With good underlying data, we can do a decent job of predicting the behaviour of numerous pipe segments over longer […]
What about the concern that a more robust methodology suffers more from lack of any data?
That is a myth. In the absence of recorded information, a robust RA methodology forces SMEs to make careful and informed estimates based on their experience and judgement. From direct estimates of real-world phenomena, reasonable risk estimates emerge, pending the acquisition of better data. Therefore, I would respond that lack of information should drive you […]
But if an estimate as to how often a pipeline segment will fail from a certain threat is needed, aren’t numbers needed to ascertain how often similar pipelines have failed in the past from that threat?
No, it’s not essential. It’s helpful to have such numbers, but not necessary and sometimes even counter-productive. Note that the historical numbers are often not very relevant to the future – how often do conditions and reactions to previous incidents remain so static that history can accurately predict the future? Sometimes, perhaps, but caution is […]