Operating safety: approaches to risk management

Increasingly, industry is talking about operational reliability. This discipline, which acquired its name and current form mainly over the last half-century in the defence, aeronautics, space, nuclear, telecommunications and transport sectors, is now useful, even indispensable, to all sectors of industry and even other activities.

The main questions this article aims to answer are as follows:

• what's in it for me (or my company)?

• What form can the use of dependability take?

Dependability is not a goal in itself, but a means or a set of means: approaches, methods, tools and a vocabulary. The goal that requires recourse to operational safety is best described as "risk control". As we shall see in this article, it is the concern to make optimal and justified decisions (the search for the "just necessary") in the face of uncertain events, in particular failures or accidents, which calls for the use of techniques for identifying, assessing, accepting or reducing risk, making up the whole of what has come to be known as operational safety.

Functional safety approaches and the characteristics that express their results make it possible to place justified, shareable confidence in a system under study (confidence in its effectiveness and safety).

The characteristics relevant to expressing the foundations of the trust that we place and wish to transmit in our system take forms (names and definitions) specific to the system in question, to the cultures of the players involved, and to their vocabularies. Fundamentally, it's always a question of availability and safety, based on basic reliability and maintainability, but the abundance of vocabularies in use in the various branches of industry (and even more so if we look beyond the industrial world) proves that everyone needs their own notions adapted to their own context.

On the other hand, approaches and methods, even when hidden under a variety of different names, are universal. It is the approaches, rather than the characteristics, that will be at the heart of this second article. In the field of operational safety (and not only there), it seems to us infinitely more important to understand an approach and reasoning, even if it means reinventing the vocabulary as you apply it, than to learn definitions and rules, to use tools and let yourself be guided by them. Unfortunately, the latter practice, which is very widespread, often leads to seriously erroneous conclusions.

Dependability is nothing more than organized, systematized common sense. To deviate from it by allowing oneself to be led by a recipe or method that runs counter to common...