Integrating Human Factors in Safety Cases: Approaches and Tools

1. Approaches to integrating human factors in Seveso II safety cases Rob Cotterill DNV Consulting

2. DNV’s worldwide network Aberdeen Oslo Stockport Stockholm London Gothenburg Seoul Essen New York Milan Kobe Piraeus Shanghai Houston Dubai Mumbai Singapore Rio de Janeiro DNV Principal Offices • 300 offices in 100 countries • 5,500 employees – qualified professionals, technical specialists and consultants PRISM Seminar, Bratislava

3. DNV and Safety Management • Development and implementation of safety management systems • Identification and assessment of the risks from major hazards • Innovative safety cases • Human factors of major accident prevention • Behavioural safety/culture change • Environmental performance improvement PRISM Seminar, Bratislava

4. The risk management agenda EXTERNALLY DRIVEN Societal Political INTERNALLY DRIVEN Business Risks Assets Image People Product “Shareholders” Economic Legal EXTERNALLY DRIVEN PRISM Seminar, Bratislava

5. Top Ten HF Issues • Organisational change and transition management • Staffing levels and workload • Training and competence • Fatigue from shiftwork and overtime • Procedures • HF in risk assessment and investigations • Communications • HF in design (e.g. control rooms) • Organisational culture • Maintenance error PRISM Seminar, Bratislava

6. Understanding human failure Slips Skill based Lapses Errors Knowledge based Human errors are not random Mistakes Rule based Routine Violations Situational Exceptional PRISM Seminar, Bratislava

7. HF approaches to risk assessment • Method 1: HF in the Safety Case • Top down approach • All human operations • Part of Seveso safety case • Method 2: HF in major accident hazards • Bottom up approach • Concentrating on MAH scenarios • Implemented into safety case PRISM Seminar, Bratislava

8. Method 1: HF in the Safety Case • Part of overall COMAH assessment: • Descriptive Elements • Predictive elements • MAPP & SMS • Technical elements • Emergency response • Source information • HF aspects in several elements • Supporting appendix of HF information • Referred to in all relevant sections PRISM Seminar, Bratislava

9. Human factors Appendix • Description of the human factors assessment of the plant • Aim: • To demonstrate that human factors issues have been taken account in the risk assessment • To show that their potential effect has been considered as a contributor to the overall risk levels arising from the day to day operation PRISM Seminar, Bratislava

10. Human factors Appendix • Identification and consideration of specific human factors issues that have led to major incidents in the past. • Application of task analysis and human error identification techniques for the assessment of safety critical operations and maintenance tasks. • Identification of the potential for violations of procedures to increase risk levels on site. • Organised according to key human factors issues : • Identification of potential for human failures. • Demonstration of control measures. • Justification of the reliance on human reliability. PRISM Seminar, Bratislava

11. Data collection • Review of MAH tables. • Site tour including discussion of activities in the following areas: • Fuel receipts. • Tank farms. • Interceptors. • Tanker loading bays. • Interviews with: • Terminal manager. • Operations staff. • Maintenance manager. • Security staff. • Demonstration of operations in the control room. • Review of site held documentation including: • Safety management system. • Key risk control systems. • Site HAZOP. PRISM Seminar, Bratislava

12. Error Analysis: Sherpa technique PRISM Seminar, Bratislava

13. High potential human error operations • Road tanker loading • Recovery from a compartment overfill (contained). • Recovery from an overfill resulting in product spillage. • Fuel receipts • Filling COC tank. • Operations tasks in and around the tank farm. • Pump inspection. • Inspection of loading bays. • Testing of Fire pumps. PRISM Seminar, Bratislava

14. Demonstration of existing control measures • Risk ranking of human errors • Linking human errors to MAH scenarios • Identifying severity of consequence & likelihood • Implementation of Control Measures and Safeguards • Driver training • Behavioural observations • Maintenance control (PtW) • Vehicle / equipment inspections • Etc. PRISM Seminar, Bratislava

15. Method 2: HF in major accident hazards • COMAH (Seveso II) compliance…demonstration of: • Evaluation of potential human error • Effectiveness of human interventions required to maintain control • Establish awareness of human factors: • Line Management • Engineering design • Technology transfer: • Develop internal HF assessment methodology • Apply to all types of activities on site • Suitable for use by non-HF professionals • Complement other risk assessment techniques PRISM Seminar, Bratislava

16. Major Accident Hazard scenarios identified from COMAH Safety Report Task inventory & criticality assessment Identify critical tasks Observational data Assessment Qualitatively assess critical tasks and potential errors Error analysis Task analysis (HTA & concurrent) Alarm & Procedure checklists Evaluate the safeguards Staffing assessment AfterAssessment Identify risk control strategies Human Factors Method to Support COMAH Before Assessment Incorporate relevant results into Safety Report PRISM Seminar, Bratislava

17. Procedure Checklist PRISM Seminar, Bratislava

18. Alarm checklist Engineering Equipment and Materials Users Association (EEMUA), 1999, Alarm Systems: A Guide to Design, Management and Procurement. EEMUA Publication No. 191. The Engineering Equipment and Materials Users Association: London PRISM Seminar, Bratislava

19. Concurrent Task Analysis PRISM Seminar, Bratislava

20. Staffing assessment Health & Safety Executive, 2001, Assessing the safety of staffing arrangements for process operators in the chemical and allied industries. Contract Research Report (CRR) 348/2001. HSE Books. See http://www.hse.gov.uk/research/frameset/crr/index.htm. PRISM Seminar, Bratislava

21. Example: Automated continuous plant • General control room duties difficult to assess • Selected a manual task, and looked at links to control room activities • e.g., communications, data entry & decision making • Example – taking sample of reactor contents • Error: fail to close circulation valve on sample cooler • Consequence: • Unrepresentative sample taken - status of reactor unknown • Potential runaway reaction • Recommendations: • Ensure all operators understand importance of sampling • Improve labelling of valves • Investigate linking valves to sample point PRISM Seminar, Bratislava

22. Example: Design phase of new plant • Multi-disciplinary team established during design phase • Applied methodology to proposed design: • Identified how plant will operate • Identified design problems before too late • Identified manning levels • Most importantly…ensured employee involvement • Example – connect road tanker to off-load point • Error: driver connects to wrong point • Consequence: • Incompatible substance into storage tank - exothermic reaction • Recommendations: • Tanker drivers not allowed on site unaccompanied • 2 x paperwork checks • Off-load points locked PRISM Seminar, Bratislava

23. Pros: identifies main activities Covers many activities Quick Low manpower requirements Cons: Can be superficial Hard to find people when you need them Might miss certain root causes Method 1: Bottom up approach PRISM Seminar, Bratislava

24. Pros: Very thorough Based on severity of MAH scenario Involves workers and supervisors High face validity Information rapidly gathered Cons: Time consuming Significant commitment from all involved Understanding of error mechanisms is required Method 2: top down approach PRISM Seminar, Bratislava

25. Conclusions • Human errors are predictable • Task analysis approach helps identify causes and consequences. • Complexity of operation should drive HEA • More complex plant requires more complex process • Commitment of time and people required for any aproach. PRISM Seminar, Bratislava

26. Any Questions? Jakýkoliv otázky? difference that counts: DNV CONSULTING Safeguarding life, property and the environment rob.cotterill@dnv.com PRISM Seminar, Bratislava