The purpose
The purpose is not to find the responsible person but to prevent recurrence. An investigation that ends at a person does not stop the event happening to someone else in the same conditions.
Time is critical
The investigation starts immediately after the event. The scene changes, traces disappear, memory loses its freshness. An investigation begun a week later has already lost half its material.
The team
One person does not investigate alone. Someone who knows the work, someone who knows safety, and someone from outside that department looking together reduces blind spots.
Reaching the root
The first cause found is usually the most visible. The question "why" is repeated until the answer falls outside the workplace's control; every answer that stays inside becomes a candidate for a control.
Closing
An investigation closes when its actions close. A recommendation without an owner and a date is not a closure.
In Optifora
The incident module ties the investigation to the record, builds the root cause diagram inside the file, turns each root into a corrective action, and does not close the event until the actions close.