Systems Engineering

Introduction to Layer of Protection Analysis (LOPA)

Is it safe enough? This can be a difficult question. Level of Protection Analysis (LOPA) is a structured method that yields a defendable answer to that question.

LOPA uses conservative, order of magnitude values for initiating event frequency, consequence severity and likelihood of failure of protective layers to approximate a risk level for any given scenario. In rigor, it falls between a typical risk matrix approach (as commonly used in HAZOPs) and a quantitative method (QRA). A LOPA is frequently performed after a HAZOP to further investigate significant findings.

Subsea Integrity Management - Inspectability & Maintainability Review

Subsea Integrity Management is defined as the management of a subsea system or asset to ensure that it delivers the design requirements while not adversely affecting life or the health of the environment throughout the required life of the field¹.

Human Error in Procedure Following

A great deal of work goes into making operating procedures accurate, but a procedure that is accurately written may be implemented incorrectly.

Studies suggest that humans conducting simple, mundane tasks make an error roughly 1% of the time. Error rates for complex tasks are much higher. Some procedures are more error-prone than others. It is incumbent upon us to write procedures that are not only accurate, but that are likely to be implemented without error.

The airline industry has dramatically decreased the incidence of human error, in part by focusing on development of effective procedures and on instilling a culture in which the procedures are actually used. We can do the same in the oil industry.

A More Effective HAZOP Process

A group of subject matter experts gather together to evaluate a design; for a plugged-in engineer, nothing is more fun than that! Yet HAZOPs are boring and exhausting for most people. That’s wrong! HAZOPs should be fun!

Picture yourself leaving a HAZOP exhausted, but hoping you can attend another one soon.

The Problems with HAZOPs

HAZOPs are not as effective as they should be. Duhon and Sutton (2010, SPE 120735) identified many reasons why we don’t learn as much as we should from HAZOPs. These insights suggest a path towards a more effective HAZOP Process.