My name is David Embrey, and over the past 30 years I have been concerned with addressing the human element in safety critical systems such as oil and gas, rail transport, power generation, aviation and healthcare. 

slide0024_image018This is the first of a series of three short articles where I will try to help engineers and safety specialists in the petrochemical, oil and gas sector to make sense of ‘Human Factors’ in Process Safety, understand regulatory concerns, and how they can make their organisations safer and more productive.

Major accidents such as Piper Alpha, Ocean Ranger, Buncefield and Texas City have led to an increased interest in the topic of Human Factors in process safety.  The HSE now expects COMAH sites to demonstrate systematic management of Human Factors issues.  Its own guidance for assessing COMAH Safety Reports states that: “…the parts that people play in protection, prevention, potential initiation, and recovery from major accidents (should) be addressed with the same degree of rigour that we traditionally expect for process and engineering issues.”  Most Chemical Engineering training provides little guidance on the topic of Human Factors, and so many plant designers and safety specialists are uncertain how to address these issues.

7780702850_d015f9bf5e_hWhat is ‘Human Factors’?  Is it the same as Behavioural Safety?  Systems Human Factors (SHF) is a particular area of Human Factors relevant to process safety.  It is concerned with optimising human performance by ensuring that the systems within which people operate are designed to take into account their physical and mental strengths and weaknesses.  A specific example of SHF would be designing the information displays in a control room so that they are easy to read, and conform to the ‘mental model’ of the process operators.  Another application would be to analysing operational tasks to identify possible errors with serious consequences, and developing interventions to minimise these risks.  SHF can also make a significant contribution to procedures development, improving safety critical communications (e.g. during shift handover), fatigue / workload issues and competency management.  In general, SHF seeks to ‘Design the task to fit the person’.

By contrast,  Behavioural Safety can be described as ‘Fitting the person to the task’, in the sense that it seeks to modify human behaviour in order to eliminate undesirable behaviours such as risk taking and lack of diligence, and to reinforce positive behaviours such as compliance to procedures.  Behavioural Safety approaches have mainly been applied in occupational safety, to address issues such as such as the prevention of slips, trips and falls.slide0026_image021

Subsequent articles in this series will focus on Systems Human Factors, since this topic is less well known in the oil and gas sector than Behavioural Safety.  In addition, SHF methods are well adapted to addressing COMAH Safety Report requirements and can be readily integrated with engineering safety techniques such as HAZOP, LOPA and SIL assessments.

In the next article, I will focus on the regulatory requirements for addressing human error and describe specific tools and techniques that are available for use in COMAH Safety Reports.

dembrey@humanreliability.com