Barrier systems and human performance expectations

I’ve shared this white paper before, but, whatever. Interesting enough to re-share.

The CIEHF whitepaper for barriers covers a lot of ground, but here’s some selected extracts:

· Controls “means all of the measures expected to be in place to prevent incidents”, and includes barriers and safeguards

· Barriers are “controls that are assessed as being sufficiently robust and reliable that they are relied on as primary control measures against incidents”

· Safeguards “means controls that support and underpin the availability and performance of barriers but that cannot meet the standards of robustness or reliability to be relied on as primary measure”

· Safeguards may include things like warnings and signs, design of alarms, HMI, procedures and more – these can’t fulfil the basic quality standards of a barrier, nor act as a full barrier system

· Safeguards may also commonly be used to ensure barrier functionality or prevent degradation of barriers (degradation controls)

· Barriers are divided into constituent parts: barrier systems, which are all of the combined barrier elements acting in a coordinated way to deliver the barrier function; barrier element, an individual component in a barrier system; barrier function – what the barrier does or its task

· Barriers can be active or passive: active barriers “are reliant on the performance either of a technical control system, of people or, most commonly, a combination of both”, and they involve detect-decide-act logics, e.g. an automated valve

· Passive controls are static and usually part of design, e.g. a bund wall

· “Human barrier elements can be either organisational or operational … Organisational barriers are where the organisation explicitly prescribes how decisions are to be taken, and/or what is to be done by means of written rules, instructions or procedures”

· “Operational barriers rely on individuals’ skill and experience, capabilities in problem solving, decision making, and imagination, as well as team working skills including coordination and communication”

· “Whether organisational or operational, the role of people in assuring the performance of human barriers will take one or both of two forms: The barrier depends on human performance to achieve its function”

· Organisations typically provide far too little evaluation or specifications of human performance expectations (see image 2)

· “Human barrier elements, whether organisational or operational, should have an associated Human Performance Standard”

· The barrier/control thinking typologies also have limitations. One is that they cannot capture the nuance of real world conditions or practices, nor human performance

· While people are often modelled as a threat to barriers, people are almost always a positive capacity – they make dysfunctional systems function and adapt

Prior posts from same document also in comments.