Incident investigation team approach

This chapter provides an overview of a management system for investigating process safety incidents. It opens with a review of management responsibilities and presents the important features that a management system must address to be effective. It examines systematic approaches that help implement incident investigation teams, root cause determinations, recommendations, follow-up, and documentation. 

This chapter addresses methods and tools used successfully to identify multiple root causes. Process safety incidents are usually the result of more than one root cause. This chapter provides a structured approach for determining root causes. It details some powerful, widely used tools and techniques available to incident investigation teams including timelines, logic trees, predefined trees, checklists, and fact/hypothesis. Examples are included to demonstrate how they apply to the types of incidents readers are likely to encounter. 

Each of these investigators is essentially following a Why Tree approach to root cause analysis. Given that there is an indeterminate number of potential chains, no incident investigation team—no matter how well qualified its members may be—can identify every one of those chains. 

There are several advantages to using a team approach when performing incident investigations. 

Unlike the procedure followed in developing logic trees, the investigation team does not construct the tree. Rather they apply each causal factor to each branch of the predefined tree in turn, and those branches that are not relevant to the incident are discarded. This prescriptive approach offers consistency and repeatability by presenting different investigators with the same standard set of possible root causes for each incident. 

Using structured approaches such as those presented in the preceding chapter, an investigation team identifies the multiple system-related incident causes. These approaches provide the mechanism for understanding the interaction and impact of management system deficiencies. When the investigators understand what happened, how it happened, and why it happened, they can develop recommendations to correct immediate, contributing, and root causes. 

This approach is not recommended for process safety incident investigation. If the team conducting the incident investigation has been chosen for their experience, technical knowledge, and skills, they are best placed to develop the recommendations to prevent a recurrence. 

The existence of an indeterminate number of root causes may help explain some of the frustration that is occasionally expressed with standardized incident analysis procedures and software. In spite of their structured approach, these systems are fundamentally subjective. For example, one technique helps the investigation team list many of the possible causes that led to an event. Some of these causes are then identified as causal factors which are then developed into root causes. Yet the determination as to which causes are causal factors will necessarily depend on the... 

This is a performance standard that allows the operator of a manufacturing plant to determine specifically how the standard is met. As long as the approach includes certain elements, the industry is compliant with the standard. While there are several elements, the most important aspect of the standard is its safety systems approach utilizing a team approach to effectively accomplish PHA of the entire operation—this approach seeks to identify the potential hazards in each step of the process and then establishes procedures to prevent or minimize serious incidents. In a sense PHA seeks to answer the questions What can go wrong and What can we do to prevent this The standard requires investigation of each incident to systematically find and remedy the root causes. 

Injuries should be investigated as soon as practical after they have occurred. Injuries that are minor in nature should be investigated by the supervisor. In some warehouses, employees from the safety committee or safety steering committee may assist in the process. Where serious injuries or incidents occur, a management and employee team approach should be used. This process may help uncover more facts, and a variety of appropriate solutions can be achieved by the group. 

If no immediate hazards are identified during the approach to the site, the incident commander will likely approve the team to enter the site and perform the site characterization. During this stage, the team will continue field safety screening at the site and conduct a detailed site investigation. 

The first stage of the site characterization process is the customization of the generic plan developed as part of planning and preparation for responding to contamination threats. In general, the incident commander will develop the customized plan in conjunction with the site characterization team leader. The steps involved in the development of the plan include (1) perform an initial evaluation of information about the threat, (2) identify one or more investigation sites, (3) assess potential site hazards, (4) develop a sampling approach, and (5) assemble a site characterization team. 

The team reviews causal factors against investigative checkiists to determine why that factor existed at the time of the incident. A combined what if/pheckfist approach may be used. 

The composition and mandate of a team will vary depending on the specific incident. Within a large organization or a company with several very different processes, it may not be practical or desirable to preselect one team to investigate all incidents. Personnel should be selected to participate in investigations based on tbeir specific skills, experience, availability, and tbe team roles tbat need to be filled for a particular investigation. Over time, tbis approach will produce a pool of trained and experienced employees familiar with the investigation process. 

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