The ETBA Worksheet

As stated earlier, the ETBA has great utility in determining the specific breakdowns in energy barriers during an accident/incident investigation. The ETBA is also quite useful in the analysis of new or existing systems to examine the adequacy of energy barriers currently in place. 

The following example will evaluate an existing oxygen supply system installed at a fictitious hospital Memorial General Hospital). 

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Complete the ETBA worksheets (Fig. 13-2) for each energy type. Use the completed ETBA worksheets to complete the appropriate type of analysis (PHL, PHA, SSHA, SHA) worksheets and report (see Chapter 8). 

Once the various types of energy affecting the system have been identified, the ETBA worksheet should be completed. Figure 9.1 shows a sample ETBA worksheet. The information recorded on the completed ETBA worksheet can then be used to perform subsequent analyses (PHL, PHA, etc.) along with their related reports. In some cases, depending upon the level of detail desired, the ETBA itself may provide an adequate amount of information to be included in the final PHA. In fact, since hazardous events can usually be associated with some type of energy transfer and, since accident causal factors typically involve the absence of controls or the failure of existing barriers and. 

Once all the data have been evaluated and the PHA worksheet is completed, a formal report should be written documenting the results of the analysis. The narrative report typically includes a summary of all significant findings associated with operational risk. Recommendations for hazard elimination/control are also included in the report as well as suggestions for follow-on analyses. Although not entirely necessary, depending on the nature of the operation, process, or system, it is also useful to include a brief description of the project itself, its purpose and/or function as it relates to overall operations. The PHA/PHL worksheets are usually provided in the report as backup data to verify the report contents. Finally, the PHA report should also include a brief discussion of the methods used to develop the analysis (ETBA, FMEA, checklists, matrices, etc.), so that the reader can validate the report data, if required (Stephenson 1991). 

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