Analysis barrier

The thought process or way of thinking about the data to get usable information from it 

The mechanics of documenting the results of that thinking in the form of organizers, tally sheets, etc. 

You can use the PBA and HBA tools as appropriate, but the use of physical and human barriers conceptually will provide you with a different perspective on accident causes and their solutions. Using the different perspectives of PBA and HBA helps to 

Identify the types of accidents as a function of how they can be prevented. 

Begin to understand what may be causing the absence of or deficiencies in these preventive measures. 

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Analyze Barriers and Potential Human Performance Difficulties During this phase of the analysis process, the barriers that have been breached by the accident are identified. TTiese barriers could include existing safety systems, guards, containment, etc. This analysis is called barrier analysis. The causal factors from SORTM are also applied in more detail. 

There are a number of tools, such as Barrier Analysis h and Change... 

Once the causal factors have been identified, the factors are analyzed using a root cause analysis tool, such as 5-AVhys or predefined trees. See Chapter 9 for a more detailed discussion of Barrier Analysis (sometimes called hazard-barrier-target analysis or HBTA) and Change Analysis (also referred to as Change Evaluation/Analysis or CE/A). In essence, these tools act as a filter to limit the number of factors, which are subjected to further analysis to determine root causes. 

Trost, W. A., and Nertney, R. J. Barrier Analysis. Idaho Falls, ID System Safety Development Center. Idaho National Engineering Laboratory 1985. (DOE/SSDC 76-45/29)... 

The process of evidence gathering, timeline development, scenario determination, and causal factor identification is somewhat iterative, and therefore some of the tools and quality tests previously described may assist in causal factor identification. More specifically, barrier analysis and change analysis, together with a completeness test, can ensure that all valid causal factors are identified. 

Causal factor identification is relatively easy to learn and apply to simple incidents. For more complex incidents with complicated timelines, one or more causal factors can easily be overlooked, however, which inevitably will result in failure to identify their root causes. There are a number of tools, such as Barrier Analysis, Change Analysis, and Fault Tree Analysis, that can assist with bridging gaps in data and the identification of causal factors. Each of these tools has merits that can assist the investigator in understanding what happened and how it happened. 

The design of most process plants relies on redundant safety features or layers of protection, such that multiple layers must fail before a serious incident occurs. Barrier analysis ) (also called Hazard-Barrier-Target Analysis, HBTA) can assist the identification of causal factors by identifying which safety feature(s) failed to function as desired and allowed the sequence of events to occur. These safety features or barriers are anything that is used to protect a system or person from a hazard including both physical and administrative layers of protection. The concepts of the hazard-barrier-target theory of incident causation are encompassed in this tool. (See Chapter 3.)... 

Barrier Analysis may he performed hy asking a series of questions while studying the timeline or sequence diagram. Typical questions are ... 

The tool helps the investigator to understand and focus on the failed harriers, which are normally identified as causal factors. These failed harriers may need to he strengthened, replaced, or supplemented, especially where weak administrative controls are highlighted. Even successful barriers that prevented more serious consequences may require reinforcement. Therefore, barrier analysis can give the investigator valuable insights into how the incident happened and some of the multiple causes that need corrective action to prevent recurrence. 

Forslind, B., The skin barrier analysis of physiologically important elements and trace elements, Acta Derm. Venereol. Suppl. (Stockholm), 208, 46, 2000. 

Develop a corrective action plan Identify all possible solutions. Using brainstorming, correlation analysis, polling, and consensus techniques, prioritize the list of solutions. Perform a barrier analysis, defining driving forces that will help the improvement process to succeed as well as restraining forces that may hold the team back. 

Another aspect that makes routine barrier analysis difficult is that the states in the gap exhibit a wide range of response times. This has been demonstrated by several groups (Spear et al, 1978 Viktorovitch et al, 1979 Snell cm/., 1979 Snell eta/.. 1980 Viktorovitch and Jousse, 1980 Beichler et al, 1980 and Femandez-Canque et al, 1983). The frequency response reported by Beichler et al (1980) for undoped a-Si H is shown in Fig. 10. The capacitance was measured over a frequency range of 10 -10 Hz. They... 

Using contributory factor framework, cause and effect method, tree diagram, barrier analysis and the five why s technique. Each contributory factor identified in the analysis could be a causal factor or an influencing factor... 

Actions should prevent or reduce the occurrence of an event resourced they should be implemented and evaluated for effectiveness through barrier analysis... 

The use of the barrier analysis technique was discussed earlier in this chapter. Barriers or safeguards can be added to a fault tree. In the case of the standard example, backflow of hydrocarbons to the tank requires failure of both the pump and the check valve (the safeguard). The addition of the safeguards is illustrated in Figure 11.17. 

Many hazard analysis and risk assessment techniques have been developed. These are just a few of the methodologies mentioned in the literature preliminary hazard analysis gross hazard analysis hazard criticality ranking catastrophe analysis change analysis energy flow/barrier analysis energy transfer analysis event tree analysis human factors review the hazard totem pole and double failure analysis. There are many other hazard analysis systems. 

A Brief Overview of Selected System Safety Analytical Approaches Working with the Risk Assessment Matrix Preliminary Hazard Analysis Energy Flow/Barrier Analysis Failure Modes and Effects Analysis Fault Tree Analysis... 

U.S. Department of Energy (DOE). 1996, Hazard and Barrier Analysis Guidance Document, EH-33, Rev 0, U.S. Department of Energy, Office of Operating Experience Analysis and Feedback, Washington, D.C., November 1996. 

Results of the nominal task analysis and detailed barrier analysis... 

The critical PSFs for the action were identified during the detailed barrier analysis from the human factors experts. They are presented in Table 1 and they refer to the field operators and field supervisor. Different human factor aspects were considered referring both to the operators characteristics (experience), the working... 

BORA Barrier Analysis and Operational Risk Analysis... 

The Barrier analysis is intended to produce a clear set of episodes for MORT analysis. It is an essential preparation for MORT analysis. The barrier analysis embraces three key concepts, namely a energy b target and c barrier . 

A barrier analysis for the Tabasco s flooding has been conducted and Table 3 shows the Barrier analysis for the present case. The results of the MORT analysis are presented by colouring-code the chart as follows a red, where a problem is found b green, where a relevant issue is judged to have been satisfactory, and c blue, to indicate where there is a need to find more information to properly assess it. Figures 5-8 show several branches of the MORT chart for the Tabasco s flooding disaster. 

Vinnem, J.E., Aven, T., Hauge, S., Seljelid, J. Veire, G. 2004a. Integrated Barrier Analysis in Operational Risk Assessment in Offshore Petroleum Operations, presented at PSAM7, Berlin, 14-18 June, 2004... 

A typical system safety task for hazard identification would be the preparation of a preliminary hazard list (PHL). Hazard identification or discovery is accomplished by reviewing lessons learned, accident reports, and other historical data. A PHL may be prepared through an informal conference, the use of checklists, and occasionally other techniques such as energy trace and barrier analysis (ETBA). 

Laundry lists of analyses frequently mix types of analyses (preliminary hazard analysis, system hazard analysis, and operating hazard analysis) with the methods or techniques for performing analyses (fault tree analysis, energy trace and barrier analysis, failure modes and effects analysis, common cause analysis, change analysis, and so on). Whether fault hazard analysis is a type or a method depends upon the reference in use. For all practical purposes, fault hazard analysis and system (or subsystem) hazard analysis seem to be the same thing, which is apparently called gross hazard analysis occasionally. 

The methods used for preparation of a PHL include informal conferencing and the use of checklists and/or energy trace and barrier analysis (ETBA). 

The recommended techniques for preliminary hazard analysis are energy trace and barrier analysis (ETBA) and failure modes and effects analysis (FMEA). Recommended techniques for system and subsystem hazard analyses are FMEA, fault tree analysis (FTA), common cause analysis, sneak circuit analysis (for electrical, electronic, and some hydraulic or pneumatic circuits) and, of course, software hazard analysis for software. 

Failure tpodes and effects analysis (FMEA) and energy trace and barrier analysis are the techniques recommended to aid in conducting PHAs. 

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