Primatech

During the performance of a PHA study it is common to periodically encounter situations where information needed to identify hazard scenarios is not available in the documents collected to support the study. Such situations often arise because study teams brainstorm and ask questions about the process that have not been posed before. In some cases, study team members may be sure of the answers based on their own knowledge of the process, which is one reason why multi-disciplinary teams are used to perform studies.

However, the answers may not be known and it is important that team members not make unwarranted assumptions which might lead to inaccurate or incorrect hazard scenarios. For example, a question might arise regarding the potential for a runaway reaction in a process at temperatures not previously considered or the team may identify the potential for two-phase flow through a relief valve but may not know if it has been sized correctly. Such items are called information needs in PHA studies. They represent information that is not immediately available but is needed to complete entries in the PHA worksheets.

Other examples of types of information needs are information missing from P&IDs or other documents, such as procedures; how the process responds to abnormal conditions; and recommendations for further study of issues after the PHA has been completed, for example, dispersion calculations for hazardous materials.

Information needs should be captured in PHA worksheets as they arise. A common practice is to record information needs together with recommendations for risk reduction in PHA worksheets. Usually the information needs are distinguished from recommendations, e.g. by flagging them with an asterisk. Responsibility for seeking answers to information needs should be assigned to specific team members who are charged with obtaining the information needed, for example, from the company’s files or by consulting subject matter experts. Team members should be tasked with addressing information needs and reporting back to the team, ideally within one or two sessions. This ensures that the previous discussion of the issue is fresh in the minds of team members and that valuable time does not need to be spent re-familiarizing the team with the issue.

It is important that PHA study teams not try to complete worksheet entries when there are information needs preventing resolution of the issue at hand. As obvious as this may seem, sometimes teams do not recognize in the heat of brainstorming that the reason they cannot resolve an issue is because they do not have all the information needed to address the matter. This can be a major waste of time in PHA studies and team leaders must be alert to the occurrence of such situations so that an information need can be identified and recorded allowing the team to move on and return to it at a later time when the information becomes available.

Of course, a study will remain incomplete until all information needs have been resolved. Time must be scheduled for the team to go back and complete worksheet entries once needed information becomes available. All information needs must be resolved before the study team disbands in order for the study to be complete.

Proper management of information needs is an essential aspect of performing PHA studies.