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Barriers to Sleep

November 19, 2013


What keeps executives and managers in the process industries awake at night? We are not aware of any survey on this topic, but a reasonable guess is that they worry about being woken up to hear that their organization has suffered a catastrophic event similar to Flixborough, Macondo, Texas City, Piper Alpha, or Bhopal. They fear catastrophes.

So how do they reassure themselves? What audit tools can help them get a good night’s sleep? A previous post in this series – Black Swans and Bow Ties – noted that the Bow Tie method for analyzing and communicating risk has gained considerable traction – in large part because it can be good communication tool. But, although normally used for hazards analyses, Bow Ties have other applications. It is suggested in this post that one of those applications is to measure the organization’s exposure to catastrophic events.

However, before looking into this use of Bow Ties it is useful to look at two other tools that can help achieve the same goal: Culture and Key Performance Indicators.


Deepwater Horizon ReportThere has been much discussion in the process industries in recent years concerning culture. For example the National Commission’s report to the President to do with the Deepwater Horizon uses the word culture many times. The following quotation from that report is representative,

It is critical . . . that that companies implement and maintain a pervasive top-down safety culture . . .

Although improvements in culture will undoubtedly reduce the risk of a catastrophic event, the practical challenge is how to measure those improvements. For example, in response to the various recommendations regarding culture from reports such as the one just cited, the Bureau of Safety and Environmental Enforcement (BSEE) issued a Culture Policy Statement. It contains nine guidance topics of which the following is representative.

3. Personal Accountability. All individuals take personal responsibility for process and personal safety, as well as environmental stewardship.

Certainly personal accountability is an important part of culture – but identifying and measuring it is a challenge. And the BSEE document provides little guidance.

OGP 456

Computer workstation isolatedThe International Oil and Gas Producers (OGP) Report No. 456 (November 2011) is entitled Process Safety — Recommended Practice on Key Performance Indicators. (The API Recommended Practice 754 is similar.) The report identifies Tier 3 and 4 Key Performance Indicators (KPIs) that can help managers understand track the likelihood of occurrence of high consequence events.

The KPIs are organized into barrier categories such as Plant Design, Safety Instrumentation and Start-ups and Shutdowns. For each barrier various Tier 3 and 4 indicators are provided. The following are examples.

Tier 3 KPI for Operational Procedures:

Number of operational shortcuts identified by near misses and incidents.

Tier 4 KPI for Hazard Identification and Risk Assessment:

Average number of hours per P&ID for conducting (a) baseline PHAs, (b) PHA revalidations.

As with Culture these barriers are difficult to assess quantitatively. Some of the difficulties to do with the above selections include:

  • The reporting of near misses is problematic. For example, if an operator takes a shortcut and is about to open the wrong valve but then realizes her error and opens the correct valve, it is unlikely that this potentially serious event will be reported. She may not even recognize that she just had a near miss. And even if she does understand she may not report the incident for fear of reprimand. What’s in it for her?
  • It may not even be obvious as to what constitutes a shortcut. No written procedure can spell out literally every step that must be taken to run a process plant.
  • With regard to the second of the above KPIs, the guidance seems to assume that the quality of a Process Hazards Analysis (PHA) will improve if more hours are spent on it. Yet a lengthy analysis may be a symptom of inefficient leadership or a poorly qualified team. A well-lead team of experts will move both briskly and effectively.

Bow Tie

Bow Tie Risk ManagementIn order to make the use of barriers more helpful to the sleepless manager it is suggested that a system is needed that meets the following criteria.

  1. Only quantifiable parameters should be used. Topics such as “personal responsibility” which are qualitative and subjective are excluded.
  2. The barriers should be should be easy to audit.
  3. The audit results should provide enough data to allow for the statistically significant  derivation of conclusions.

One way in which the above requirements could be addressed is as follows.

  1. Develop a series of bow tie diagrams covering a range of different types of operating and maintenance activities.
  2. List the barriers in each diagram.
  3. Conduct regular audits to determine the quality of the barriers. Assign a value to each barrier: ‘0’ broken, ‘1’ degraded, ‘2’ functioning.
  4. Develop a spreadsheet to measure trends. If there are say 20 bow ties with an average of 30 barriers each then a perfect score is 20 x 30 x 2 = 1200 points.
  5. Repeat the audit frequently so as to develop trend lines.

Barriers should be strictly verifiable. For example, the barrier “High level alarm sounds” can be readily checked. The barrier “Instrument technician trained” can also be checked by reviewing training records, although this is slightly more subjective since attendance at training does not assure competence in the field. The barrier “Instrument technician takes shortcuts” is almost impossible to validate — at least in the short term — so it should be excluded from the list.

Clock-2If the number of failed barriers is low, and if the trend line is favorable, then the manager can go to bed confident that the only thing that will wake him is the alarm clock (or the Black Swan mentioned at the start of this post).

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