Why 10% of Your Operations Cause 50% of Your Safety Incidents

When it comes to safety, the adage “an ounce of prevention is worth a pound of cure” is one most businesses should heed. It is well-understood that equipment that is in a poor state of repair is more dangerous than equipment that is well maintained within environmental, health, and safety (EHS) regulations and standards.Click here to speak with Dan

One needs to look no further than their own car for proof. Poorly inflated and nearly bald tires are far more likely to fail and cause an accident than properly inflated tires with ample tread. Spending a few minutes each month to check tire inflation and examine tread depth, replacing tires when needed, is far more cost effective and clearly safer than having an accident; and having to repair or even potentially replace the car due to a blow-out. Even in situations where failure is not catastrophic and there is no injury as a result of the failure, failures still can contribute significantly to poor safety.

The 10% Factor

 In 2010 Scott Ostrowski and Kelly Kelm of ExxonMobil Chemical Company, published an article in Chemical Processing that cited a 1998 study of 500 safety incidents (collected in 1996) published by the UK Institution of Chemical Engineers as the source of the data point “A typical refining or petrochemical facility will spend less than 10% of its time in transient operations — yet 50%+ of process safety incidents occur during these operations.” This statistic has become embedded dozens of reliability-focused presentations at many conferences since that time.

While updated data that validates this statistic today is not readily available, the general industry consensus is that it is essentially correct. Intuitively, this appears to be reasonable. Looking at data in the World Offshore Accident Database (WOAD), a record of all safety incidents in the offshore segment of the oil and gas industry, it is clear that most accidents occur during times of either equipment failure or startup/shutdown of the process. Very few of the incidents in the WOAD occur as a result of natural disasters or failures (such as a geological incident) interrupting normal operations or from process upsets that occurred due to material changes (such as hitting a gas pocket instead of a crude deposit).

Just What Are Transient Conditions & What Causes Them?

Basically, in any process there are really only two basic states. Either the process is operating in steady-state where it is essentially “on cruise control” or it is in-transition. Transitory states occur either during process upsets or during times when the process is intentionally changing from one steady state to another, such as starting up or shutting down the process. Clearly, any time a piece of process equipment fails while in use it causes a process upset so a failure related to poor reliability is at the heart of this type of problem. Poor reliability also contributes to transient operations even when there is no apparent process upset. For example, if a seal starts to leak and maintenance needs to take the equipment offline to repair it, even though production is not being directly affected, the shutdown-startup cycle occurs.

Why Safety Incidents Occur 53% of the Time During Transient Conditions

If we accept the 1998 IChemE statistic as still being more-or-less valid it drives the question, “why are transient operations so much more prone to safety incidents?” One of the key reasons is simply because by spending 90% of their time in steady state operations, people just are not “practiced” enough in safely performing their jobs during those transient times. Also, since things can rapidly change during the transitory period, human capabilities for dealing with change may impact reaction or reasoning times. In some cases, it can be attributed to not having adequate training for the transient conditions or lacking proper process documentation on safely navigating the transient conditions.

The Reliability Connection

From the examples above it becomes clear that having reliable operations that stay in steady state most of the time, with minimal shutdowns and startups for maintenance activities, is a major contributor to reducing safety incidents. In fact, one of the key findings of the US Government after-incident analysis of the Deepwater Horizon accident in the Gulf of Mexico in 2010 was that a “poor safety culture” is a key contributor to accidents and that one of the attributes of a poor safety culture is poorly maintained equipment. The bottom-line is that a highly reliable facility is generally indicative of a good safety culture. There is a clear link between reliability and safety, and any manager or executive that wants to improve their safety performance should look to improving their reliability performance according to ReliablePlant.

At LNS Research we concur.

NEW Research Spotlight on strategies and recommendations for minimizing risk through a migration away from monolithic, single-plant MOM architectures through exploration of Cloud and IIoT technologies that are advancing in manufacturing today.