Technical change

The purpose of this article is to provide some guidance on how to implement technical and engineering changes without having a negative impact on human reliability. (Assessing the impact of organisational change has been discussed in a separate article).

The nature of technical changes

These will vary considerably, depending upon the industry or sector, but some examples of technical changes (or “modifications”) are as follows:

Equipment changes:

• layout or location of equipment
• changes to set-points of critical instrumentation or alarms
• introduction of new tools, machinery or technologies
• decommissioning or disposal of assets
• updated process control system
• increased levels of automation.

Process changes:

• new raw materials or feedstock
• change to how materials are delivered
• new construction materials
• increase in process parameters, such as temperature or pressure
• increase or decrease in throughput at the facility
• changes to the direction of liquid flow.

These changes may be undertaken to improve efficiency, extend the life of an aging facility, or simply because a new technology has become available. For example, on a chemical facility, raw materials that were previously available in drums may now be delivered in bulk by a road tanker into a large storage vessel. This change would impact how people on the facility handle these raw materials, and may introduce new types of human failures (e.g., relating to the connection and disconnection of flexible hoses to transfer materials from the road tanker to site). So, although manual handling of drums may have been eliminated, new hazards may be introduced by the change.

Management of technical change

Companies may have a Management of Change (MOC) process for assessing such technical changes. This process (if suitable and followed) should recognise that technical changes can impact on health and safety outcomes (including major hazards/process safety). The MOC process should identify and manage the risks from both temporary and permanent changes. This formal assessment process is especially important for changes to Safety Critical Elements (SCE), where failure could lead to a major accident.

However, a failure to adequately review proposed technical changes has been a contributory factor in many significant events across a range of industries. For example, approximately a third of all incidents investigated by the US Chemical Safety Board (CSB) between 1998 and 2015 involved issues in managing technical changes. Deficiencies can arise because changes are not considered to require a formal review, the MOC process is not adequate, or a review of changes is not undertaken for expediency.

In the Grenfell Tower disaster in London (2017), the exterior of the building was modified with aluminium panels (cladding) to improve its aesthetics. These panels contained a highly flammable polyethylene foam insulation that contributed to the rapid spread of fire on the outside of the building. This technical change led to the escalation of a small electrical fire in one of the apartments into a disaster that took the lives of 72 residents.

A permanent modification to the Nimrod aircraft to enable air-to-air refuelling introduced a design flaw that played a crucial role in the loss of Nimrod XV230 in September 2006. Opportunities to identify this design failure, and therefore prevent the disaster, were missed.

Perhaps the most famous example of temporary change is a pipe installed in a factory at Flixborough, in the UK, in 1974. The temporary pipe failed after two months, causing the release of hot cyclohexane. This mixed with the air and exploded, killing 28 people and destroying the chemical plant. Because of this incident, many companies developed procedures to manage technical changes.

“The disaster was caused by the introduction into a well designed and constructed plant of a modification which destroyed its integrity” (Flixborough disaster Inquiry, 1975, para 209).

In an example described by Trevor Kletz in his book “What went wrong?” (2009), the heating in a building had to be shutdown over a weekend for repairs. Due to concerns that the water in the sprinkler system might freeze, it was replaced with ethanol. Unfortunately, a fire occurred in the building – which was made worse when the sprinkler system activated !

The potential impacts of technical change need to be assessed to ensure that it does not:

• create an incident that has not been previously identified
• increase the likelihood of an identified safety incident
• increase the magnitude or severity of an incident.

If managed well, technical changes can of course improve safety and business performance.

Technical change and human factors

Technical change may introduce new failure modes that impact on the integrity of a facility, but these should be managed by the existing risk management process. In this article we will consider how these changes impact on how people work, or how people interact with the system.

Therefore, a company Management of Change (MOC) process should also assess how technical change can impact human reliability on critical tasks. My experience is that this is not always addressed in the MOC process, or is addressed in an unstructured manner. For example, technical changes may require people to process new information, acquire knowledge, or interact with different people.

“We are becoming aware that the major questions regarding technology are not technical but human questions” (Peter Drucker, 1967)

The MOC process will require an assessment of hazards and risks associated with the change, which should include how the change may impact on human performance. (Especially performance on critical tasks).

Key principles in managing the human factors aspects include:

1. The assessment effort should be proportionate to the complexity of the change and the degree to which the change may impact on the management of safety.
2. People affected by the change should actively participate in the assessment, so that knowledge of their work (and how it is really done) is fully considered.
3. The cumulative effect of a number of different technical changes should be considered (even if each change has been assessed individually).
4. Lessons from previous changes, including incidents, should be considered in the assessment.
5. Identified issues should be addressed before changes are implemented.
6. A review should be conducted after implementation, to ensure that emerging issues are identified.

Assessing the impact on human factors

Modifying (or introducing a new) system, process, or equipment often changes what people are expected to do. This section outlines two approaches to support an assessment of the impact of technical change(s) on human reliability. Think of them as different lenses to examine how tasks may be impacted by change. These options are not independent and so you may decide on a blend of the different approaches.

Option 1: Analysis of tasks

This is essentially a Human Reliability Assessment – understanding the human activities that are important to safety (or any other outcome that you’re interested in, such as quality or efficiency), and then assessing what might go wrong during the performance of those tasks as a result of change. In some industries this is known as Critical Task Analysis. In order to understand the impacts on human performance, it is necessary to identify what is being changed, who will be impacted by the change (both directly and indirectly) and in what ways they will be affected. Changes may make certain types of human failures more likely (both unintentional errors and work-arounds).

In summary, this requires an assessment of the tasks that people perform, and how the change alters these tasks (such as adjusting the frequency of a task, requiring new knowledge or skill, requiring a faster response, or changing the work environment).

Example issues include:

Competence: inadequate knowledge, skills or experience for the new equipment or process; increased training demands; technology reduces hands-on experience in the field

Procedures: out of date, missing or inconsistent following change; emergency plans fail to incorporate new equipment; technical drawings become inaccurate

Situation awareness: new equipment makes key information less salient, or in a different format; the introduction of different operating “modes” causes confusion

Communications: higher noise levels on new equipment make verbal communication difficult

Workload: increased alarm handing by control room operators; additional roles and responsibilities absorbed by existing personnel; increased distraction from new technology

Fatigue: additional computer screens leading to visual fatigue; increased monitoring tasks leading to monotonous work.

Note that a change in tasks for one workgroup can have indirect effects on other teams or departments. For example, if a technical change makes it much easier for operational staff to take samples, this may increase the workload of laboratory staff who perform tests on those samples.

Option 2: Scenario assessments

Scenario assessments help to ensure that people will be able to manage high demand situations following a change. This analysis can be applied to ‘trial run’ a technical change before any irreversible steps are taken.

Scenario assessments are useful where the proposed change impacts personnel who have a direct role in responding to major upsets or emergencies. Scenarios may be taken from your risk assessments, emergency plans, safety case, incident reports etc.

Once a scenario has been selected, identify the tasks that people perform to prevent the initiation of an event and those tasks that mitigate the consequences should an event occur. Then, assess how the proposed technical change can impact human performance on these critical tasks.

The analysis may involve a walk-through of tasks with personnel at the actual worksite, a desk-top exercise, or a combination of the two. Your analysis might consider:

• who will be impacted by the technical change? (consider non-routine tasks, such as those performed by maintenance personnel)
• how will a developing incident be detected?
• will people have the necessary skills and experience to manage the scenario?
• will different equipment or technologies confuse people in the heat of the moment?
• if the change leads to different operational philosophies or “modes”, will people know which one is appropriate in this scenario?
• is new equipment perceived to be informative and reliable (i.e., is it trusted)?
• do new technologies support effective decision-making (especially under duress)?

A company Management of Change (MOC) process should have a requirement to consider human factors issues as part of the process. This will include the need to involve employees (and others who are impacted, such as contractors). It should assess human factors risks and opportunities resulting from the change (i.e., where you want to get to) as well as risks during the transition period (i.e., how you get there).

Feedback from staff, and performance measures, should be monitored during and after implementing the change.

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