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PSM: Displaying Human Factors Using Bowties

September 19, 2017 | 10:00 - 11:00 am CDT

The Chemical Center for Process Safety (CCPS) issues books that have become the de facto best practice for process safety management (PSM) globally. A new CCPS Concept book prepared with the UK Energy Institute will be issued in 2017 to standardize using the Bowtie Method in risk management. The book will provide a description of human factors and introduce the concept of multi-layer bowties for this description.

Our webinar presenter has been actively involved on the committee writing the new concept book, Guidelines for Barrier Risk Management (Bow Tie Analysis). The first webinar in this series, PSM: Risk Assessment Using Bowtie Analysis, summarizes the key elements of the book. This session focuses on the human factor elements and use of multi-level bowties to demonstrate how safety culture elements actively prevent major accidents.

Multi-layer bowties provide the clear link between a positive safety culture, process safety leadership, etc. and preventing major accidents. Sharing these bowties with operators will support positive safety culture efforts.

Key insights covered in this webinar include:

  • In "standard" bowties, human error should preferably not be directly modeled as a threat that can lead to a top event; rather they are inherent activities from normal operation.
  • Active barriers with Detect, Decide and Act components often involve humans in one of the elements; so it is important to understand how these can be degraded.
  • Safeguards are then needed to prevent this from happening.
  • Many of the controls that organizations use to minimize human error are important safeguards to prevent degradation of barriers. Safeguards can range from local warnings and signs; the design and implementation of alarms and the human machine-interface to control systems; through job design, operating procedures and cross-checking practices; to specific training, etc.
  • More detailed bowties (Extension Level 1, Extension Level 2, etc.) show how those safeguards can be degraded or defeated and how safety culture elements (e.g. training, competence, STOP culture [the willingness of frontline personnel to stop work if they have any concerns over safety], leadership, etc.) can actively prevent a major accident.



Mark Manton

Mark Manton is Principal Consultant for ABS Group based in Warrington, United Kingdom (UK). He has 30 years' experience in the oil and gas industry. After acquiring a PhD in Chemical Engineering at MIT, Manton spent 25 years with Shell in roles located in Amsterdam, The Hague, Bintulu (Malaysia), Rouen (France), Chester (UK) and London. His last role at Shell was as Process Safety Manager at Shell’s Stanlow refinery. During that time he was part of, and for 2 years chaired, the UK Petroleum Industry Association's (UKPIA's) Process Safety Leadership Network, the main interface between the sector and the Health and Safety Executive (HSE) and the Environmental Agency (EA). This also included active involvement in working groups covering Human Factors, Buncefield follow-up and environmental risk assessments, providing extensive experience working directly with the UK HSE to demonstrate that the residual risks have been reduced to ALARP.

Manton has provided consulting and training services to Shell, the US Bureau of Safety and Environmental Enforcement, KPC, Syngenta, Takreer, Valero, Wood Group, Calor, Slovnaft, Hexcel, Evonik, Merck, SBM Offshore and GKN. He is an active member of the committee writing the CCPS/EI concept book on Risk Management using Bow Ties and has presented papers at conferences organized by IChemEand AiChE.

About ABS Group

ABS Group of Companies, Inc. (, through its operating subsidiaries, provides technical advisory and certification services to support the safety and reliability of high-performance assets and operations in the oil, gas and chemical, power generation, marine, offshore and government sectors, among others. Headquartered in Houston, Texas, ABS Group operates with more than 1,500 professionals in over 30 countries. ABS Group is a subsidiary of ABS, a leading marine and offshore classification society.

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