Maintaining Chronic Unease

Article by Phil Eames CEng FIChemE

What keeps you awake at night?

THE previous two articles in this series focused on maintaining the basis of safety for our processes through operational discipline and understanding the way that this can be undermined through complacency and drift (the phenomenon of normalisation of deviance). One way to fight complacency and drift is to establish and maintain a state of “chronic unease” in the organisation by means of appropriate process safety performance indicators, which is the subject of this article.

As an experienced HAZOP facilitator I have become used to hearing  in both repeat (“redo”) and revalidation studies  about operational or reliability issues that the plant is experiencing.  Examples are:

  • “Oh, the controller wouldn’t fail like that because we have to run this loop permanently in manual control”;
  • “This unit has never worked properly since it was commissioned";
  • “That equipment has never been inspected or tested”; and
  • “But the alarm wouldn’t be any use because the process always runs at a higher pressure than that”.

Such observations are often accompanied by a weary-sounding: ”We’ve raised it with management but nothing has been done.” I am always concerned to hear such things because it suggests that the plant is running in an abnormal or sub-optimal way and that management may have stopped noticing. Many of them suggest that normalisation of deviance is at play and that the level of process risk may be higher than management realises. We know that the risk of incidents is higher when the process operating in an abnormal or non-routine mode, so how can we make sure that information like this is on management’s radar?

Process safety performance indicators

The concept of process safety performance indicators (PSPIs) has been around for at least a decade now; their purpose being to draw attention to process safety performance and drive ongoing improvement. There are a number of commonly-used guidelines for generating PSPIs; examples are The UK Health & Safety Executive’s guidance HSG 2541 and the American Petroleum Institute’s recommended practice API 7542.

HSG 254 is based on the principle of identifying linked pairs of leading and lagging indicators to drive process safety improvement on specific issues. The success of this approach depends on choosing the right issues to address and selecting appropriate indicators to work on.

API 754 and its four tiers of indicator is based on the generation of data from incidents or abnormal occurrences. Tiers 1 and 2 relate to loss of containment incidents, Tier 3 to occurrences involving challenges to safety systems and Tier 4 to occurrences involving loss of management control. The success of this approach depends on the quality of the incident reporting system.

What keeps you awake at night?

The HAZOP experience I described above, and many discussions on many sites over the years, suggest that there is a more direct way to develop indicators that  can immediately create a sense of “chronic unease” within the organisation, while at the same time promoting operational discipline. This is to ask some simple, but probing questions. My “top 10” questions are itemised in the table below.

Ten essential questions for operating sites

  • Which control loops are operating permanently or frequently in manual control?
  • How many process alarms are permanently in alarm, suppressed or shelved?
  • What is the frequency of demands on your protective systems?
  • Which protective systems (or safety critical elements) are unavailable (failed, out-of-service or overridden)?
  • What is the frequency with which protective systems (or safety critical elements) fail proof tests?
  • What items of equipment are operating outside design limits or in spite of failed inspection or proof tests?
  • Which equipment is operating with routine inspections or proof tests overdue?
  • How many temporary repairs are in place?
  • What is the frequency of unplanned process shutdowns (and therefore start-ups)?
  • What is the frequency of intrusive maintenance on hazardous process systems?

I would consider these to be questions that every operation should be able to answer, and could be developed into essential, or core, PSPIs. They relate directly to the basis of safety and reinforce the relationship between process safety and reliability engineering.

“Chronic unease” is generated by asking the question: “How would it look if a serious incident happened relating to such equipment?” PSPIs developed from the answers to these questions can be used to drive improvements in operational discipline, which in turn will foster (in time, with consistent leadership) a stronger process safety culture in the organisation.

And of course we should never forget that there is always information out on the plant, such as evidence of loss of containment (sight and odour), equipment in visibly poor condition and out-of-date operating instructions.

So don’t wait for operators to raise issues in HAZOP meetings. Try and avoid generating large numbers of PSPIs based on published guidance. Go out and ask your people what concerns them, ask the essential questions listed above and add the judgement of your eyes and ears out on the plant!

In the final article in this series, we will examine the subject of learning from incidents both inside and from outside the organisation.


1. HSG254, Developing Process Safety Indicators: A Step-by-Step Guide for Chemical and Major Hazard Industries, HSE Books, 2006.
2. ANSI/API Recommended Practice 754: Process Safety Performance Indicators for the Refining and Petrochemical Industries, 1st Edition, API Publishing Services, April 2010.

IChemE’s Process Safety Performance Indicators and PSM Auditing course provides a more detailed exploration of this topic. Additional guidance is available from the IChemE Safety Centre’s Guidance:  Lead Process Safety Metrics – Selecting, Tracking and Learning (2015).

Article by Phil Eames CEng FIChemE

An IChemE Fellow and an independent consultant. Eames has worked on process safety in most sectors of the process industries including oil and gas, petrochemicals, pharmaceuticals, power generation and water. He is also a trainer for IChemE, delivering a range of courses including the HAZOP Leadership and Management course

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