How many people are normally involved in a root cause analysis investigation?
The number of people involved in an investigation depends primarily on two factors – the magnitude of the problem being investigated and the investigation quality level desired. Most of the time required to complete an investigation is used in the collection of information and other data (usually at least 75%). The person, or persons, who were injured, made an error, or discovered an equipment problem is normally questioned first, along with any witnesses. Subject matter experts (SMEs) are then questioned. I have found that the number of subject matter experts you choose to involve is what affects the total number of people involved AND the quality of the investigation itself the most. High levels of investigator skill (the ability to ask a lot of great questions while also keeping a very open mind for example) can reduce the number of SMEs involved to some degree, but the same rule of thumb still applies – more human input, better results. Additionally, the amount of non-interview dat
