EECC investigations developed in five distinct phases.

1. Information, evidences and data collection

Relevant information in different forms (Site surveys and site visits, technical documentation, operational data ) are collected by EECC personnel, by visiting the site and surveying the works done on site, by formally asking for specific support and information, and by researching available specialist documentation.
Scope of this introductory step is to acquire all the information collected during the previous years by the entities involved in the operation and maintenance of the equipment, and obtain the data related to the event.

2. Documentation study

The first investigation step usually includes the study of the technical reports and document as record of the planned and unplanned maintenance works performed in the past.
Scope of this step was to ascertain the operational history of the equipment and highlight (if any) upgrades, incidents, recurring issues, chronic problems, abnormal events, etc.

3. Evaluation of the operational data

Operational data collected before the event by the DCS are first evaluated to look for any anomalies or singularities, which could give hint of any on-going failures or existing problems of any nature.
Usually, the recorded values are evaluated in relationship with the warnings and the alarms released during the same period, with the aim of determining a correct time sequence of the event.

4. Root cause analysis

This phase includes the analysis aiming at identifying the root cause, i.e. the factor that, if removed, could prevent the recurrence of the adverse incident.
Main purposes of this step is to understand the failure mechanism that lead to the extended damages, thus giving a first hint to identify the cause(s) of the event. Different factors possibly being considered as the root cause are then identified. Each factor is assessed and discussed, to evaluate its plausibility in relationship with the event. The most likely factor(s) are then considered as the root cause of the event.

5. Search for the triggering factor

The triggering factor is the origin of the event, i.e. the first step in the time sequence. It is the causal entity/object/episode that pushed the system in an instable condition that finally caused the event to happen.
As far as possible, the triggering factor should be identified to enable an appraisal of the responsibilities related to the accident.