Topic: Modeling

Note: the following answers are short and direct, sometimes omitting information that might be helpful for full understanding. Please consult your copy of the book or other resources on this site for more complete answers.

Statistical Life Valuation

As monetization of risk becomes more mainstream, values must be assigned to the potential for human injury or fatality.  The risk assessor need not generate values himself since such numbers are published in various sources.  This includes values that have been used in US government decision-making for years. Here is some example guidance:  VSL Guidance 2013 […]

Can you explain more about Geohazards and Weather-Related Outside Forces?

Geohazards and Weather-Related Outside Force The threat category ‘Outside Force’ in a risk assessment typically includes forces such as ground/earth movement, flooding, cold weather, and lightning. When buried pipelines cross sloping terrain, there is a danger that soil movement (down the slope) will impose an excessive load on the pipe that could lead to failure.  […]

Optimizing the use of Inspection Results

A limitation that continues to plague older risk assessment methodologies is the inability to fully include the results of inspections.  None dispute the value of inspection and its critical role in failure avoidance.  Yet, neither the classical statistics-centric QRA nor the common relative risk ranking methodologies, can capture inspection activity in a meaningful way. A […]

Risk Profiling

Pipeline Risk Assessment—Risk Profiling In earlier installments of this column, we introduced the concept of pipeline risk assessment Essential Elements (EE’s).  That guideline is a list of ingredients that must be included in any pipeline risk assessment before that assessment can be considered complete.  Following these guidelines helps to ensure a technically sound risk assessment […]

How do we Assess for Geohazards?

Many miles of pipeline around the world are subject to damage from geohazards.  As used here, ‘geohazard’ refers to any earth movements sufficient to damage a pipeline, and can also include weather- and water-related events that are potentially damaging.  So, we often group, under the heading ‘geohazard’, a wide range of phenomena such as: landslide […]

Pipeline Risk Assessment

Risk assessment on any facility is most efficiently done by first dividing the facility into components with unchanging risk characteristics. For a cross-country pipeline, this involves collecting data on all portions of the pipeline and its surroundings and then using this data to ‘dynamically segment’ the pipeline into segments of varying length. Risk algorithms are […]

ILI vs DA—The Risk View

A rather common issue these days is decision making involving comparisons between In Line Inspection (ILI) vs Direct Assessment (DA, and, in particular, External Corrosion DA or ECDA).  You may need to research these techniques, if not already familiar to you, since we will assume the reader is fairly familiar with both. Both are acceptable […]

Is this the same as SRA, LSD?

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 […]

Pipeline Reliability–Service Interruption As ‘Failure’

Generally, a pipeline’s reliability includes consideration of all leak/rupture scenarios PLUS all other scenarios that could prevent the system from performing its intended function.  With the normal ‘intended function’ being something like:  deliver product to point B from point A at specified flow rates, pressures, temperatures, and product quality, a reliability failure occurs when any […]