From HAZOP to SIMOP – Understanding Key HSE Terms For Action Management

The HSE industry is not unique in its use of acronyms to describe key processes/methods etc, but it must have more than most. In an action management system, when a specific action needs to be undertaken, completed and tracked, it is vital that everyone involved understands exactly what is required. 

I remember working for an offshore survey company in the 80’s and plucking up the courage to ask someone what ‘KP’ meant (it means ‘Kilometer Post’ in case you’re interested!) This was important information that I wish someone had told me up front and I’m sure the same thing happens in all kinds of professions.

We want to help avoid those tricky conversations so we’ve put together a short (and definitely not comprehensive) list of the key terms we’ve seen in the last 20 years of delivering our ATMS action tracker. One thing that relates all of these is that they can all result in an action (or actions) which has to be performed and closed out. ATMS was built to handle any type of action but the list below represents what are probably the most frequent action types our clients deal with.

HAZOP (Hazard and Operability Study)

HAZOP is a detailed, systematic method used to identify potential hazards and operability problems within industrial processes. It involves a team reviewing process designs and identifying what could go wrong if there are deviations from normal operating conditions. Each scenario is assessed for potential causes and consequences, helping to develop strategies to mitigate these risks.

HAZID (Hazard Identification Study)

HAZID is used to identify hazards in the early stages of project design and planning. It involves a team that assesses scenarios that could lead to hazardous events. Hazards are ranked based on their potential impacts and likelihood, guiding the prioritisation of safety measures.

SIL (Safety Integrity Level)

SIL refers to levels of risk reduction provided by a safety function. SIL levels range from 1 to 4, with SIL 4 representing the highest degree of safety. The level is determined based on a target failure measure; higher SIL levels correspond to lower probabilities of failure on demand.

LOPA (Layer of Protection Analysis)

LOPA is used to analyse and ensure adequate safety levels in processes involving high-risk scenarios. It assesses existing safety layers and determines if additional measures are required, providing a methodical approach to achieve acceptable risk levels.

MOC (Management of Change)

MOC is a structured system that manages safety, health, and environmental risks associated with changes in processes, personnel, or equipment. It ensures all changes undergo thorough review and approval processes to maintain safety and compliance.

ALARP (As Low As Reasonably Practicable)

ALARP is a principle that aims to minimise risks as much as feasibly possible, balancing risk reduction against effort, time, and the costs of achieving it. It’s widely used in risk management to ensure that risk levels are both tolerable and cannot be reduced further without an inordinate amount of resources.


The Bowtie Risk Assessment Method is a powerful visual tool used for analysing and managing specific risks. It graphically depicts the relationship between potential hazards, their possible causes, the resulting events, and their consequences, creating a “bowtie” shape. At the centre of the bowtie, the hazard is linked to a top event, which represents a critical point where control is lost. On the left side, preventive barriers are placed to stop the top event from occurring, while on the right side, mitigative barriers are set up to reduce the impact if the top event does occur. This method helps organisations clearly understand and communicate risk management strategies, identify weaknesses in controls, and prioritise safety measures by visually mapping out the pathways from hazards to potential impacts.

HIRA (Hazard Identification and Risk Assessment)

HIRA is a comprehensive approach that involves identifying potential hazards and assessing the risks associated with these hazards in a workplace or during a project lifecycle. It helps in determining appropriate ways to eliminate or control the risks.

SIMOPS (Simultaneous Operations)

SIMOPS refer to the practice of performing multiple operations concurrently at a single facility or location. These operations often pose intersecting risks, requiring careful coordination and robust safety protocols to manage the increased risk potential effectively.

EERA (Escape, Evacuation, and Rescue Analysis)

EERA focuses on designing strategies for personnel safety during emergency situations. It involves assessing the effectiveness of escape routes, evacuation procedures, and rescue options available on facilities, particularly in the offshore industry.

ESSA (Emergency Systems Survivability Analysis)

ESSA, or Emergency Systems Survivability Analysis, is crucial in assessing the robustness and effectiveness of emergency systems under potential hazard conditions. This analysis involves evaluating the ability of critical systems to continue functioning during and after an emergency event. The focus is on ensuring that essential systems such as fire suppression, alarms, communication networks, and emergency power supplies remain operational during disasters to facilitate safe evacuation and emergency responses. ESSA is integral to designing facilities that can withstand adverse conditions, thereby enhancing the overall safety of the operation and its personnel.

When you are managing actions or tracking progress of actions, it is helpful to understand exactly what you are tracking and in the HSE field, where the safety of individuals is at stake, the clearer you can be, the better.  These acronyms are commonly used in an action management system, and so you will be familiar with them when you next encounter them during your work.

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