In our universe nothing is ever permanent! There will always be unforeseen events, incidents that will appear at all times. This is even more true in our field of expertise: “bugs”, human errors, hardware and software crashes, errors linked to daily changes and evolutions,… In short, a long list of parameters which can generate incidents and induce losses which can be critical. It is therefore very important to be able to define, identify, avoid and especially in the worst case to be ready to solve them!