Incident investigation generally

General guidelines for conducting process incident investigations are given by CCPS (2003). Specific practices that relate to the nature of chemical reactivity hazards are discussed below. 

The Center for Chemical Process Safety (CCPS) conducted a survey of its membership and other processing companies in preparation for this revised edition. Based on the responses, some general observations can be made about incident investigations ... 

Each event, such as equipment failure, process deviation, control function, or administrative control, is considered in turn by asking a simple yes/no question. Each is then illustrated by a node where the tree branches into parallel paths. Each relevant event is addressed on each parallel path until all combinations are exhausted. This can result in a number of paths that lead to no adverse consequences and some that lead to the incident as the consequence. The investigator then needs to determine which path represents the actual scenario. Generally, a qualitative event tree is developed when used for incident investigation purposes. 

Investigators are not out to assign blame. Actions taken to blame and shame generally do little to prevent similar incidents from occurring. Therefore, it is necessary to foster an open and trusting environment where people feel free to discuss the evolution of an incident without fear of reprisal. Without such a supportive environment, involved individuals may be reluctant to cooperate in a full disclosure of occurrences leading to an incident and the incident investigation may be concluded prematurely with the root causes left uncovered. 

Best practices in incident investigation have evolved substantially in the last 20 years. The general approaches to incident investigation are discussed in Chapter 4. This chapter will describe more thoroughly the tools and techniques used in incident investigation. 

Words and phrases such as incident, accident, and near miss tend to be used quite loosely in general conversation. They also tend to have different connotations in English, American, and Canadian usage. However, in the context of formal incident investigation and analysis such words need to be tightly defined. The definitions used for these terms in this chapter are provided below. 

The incident number is a unique identifier that will be used for all investigation and analysis work to do with this incident. Generally, the number will be assigned by the incident investigation software and will never be changed or reused. 

General discussion and guidance to do with professional writing in general is provided in Chapter 16. Additional issues to do with the writing of an Incident Investigation report are discussed here. 

One of the general features of SEMS is that companies are not required to submit a program or plan. They must simply have the program in place such that they are ready for an audit (or incident investigation). There are, however, a number of exceptions to this generalization—and this 30-day requirement is one of them. 

General observations deriving from the study follow. They are just that— observations resulting from a subjective review of a limited number of reports, the 537 reports received. I do suggest that these observations deserve a broader consideration through a study that would meet the requirements of good science since the subject — incident investigation — is so important. 

Generally, few supervisors did a good job of ergonomics problem identification. Although there has been an emphasis on ergonomics as a significant aspect of the practice of safety, that emphasis was not seen in the content of the incident investigation reports reviewed. 

Plan Plant general manager decides that he will lead an incident investigation for all forklift incidents in order to get to root causes and corrective actions. 

In each incident you should ask yourself (1) What happened (2) How did it happen (3) Why did it happen This series of questions is one form of root cause analysis (RCA), a standard procedure in the investigation of incidents in business and industry. The last question is the most important one and you will find you may have to ask and answer this question several times in sequence before you come close to the real or root causes of an incident. RCA generally recommends asking Why five times to get to a fundamental, rather than superficial, cause. Root causes are the basic causes of an incident that can be reasonably identified, that can be controlled, and for which recommendations or lessons learned can be derived. Many times root causes are not immediately obvious, but can be identified from careful inquiry. Once you know the root causes you should be able to develop recommendations or steps to prevent this from happening again. 

This is a relatively brief and inexpensive book that comments on the general incident investigation process, and on several investigation and analytical techniques, such as Events and Causal Factors Analysis Change Analysis Tree Analysis and Specialized Computerized Techniques. 

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