" We chose the quality because the luck had become too expensive. " (Jean Abraham) " In the running in the quality, there is no finishing line. " (David Kearns) " The quality is never an accident; it is always the result of an intelligent effort. " (John Ruskin)

The studied system is represented by the diagram on the following page which represents the installation of nitration of the product "X" by a nitriding mixture in excess. This operation is carried out uninterrupted in four engines in cascade. After drying, the product "X" is introduced into the first three apparatuses. The reaction is exothermic and requires a permanent cooling by the intermediary of a double outer jacket and an interior crown. Moreover, a very important agitation of the bath is essential. Each aircraft is equipped with a valve with fast opening allowing draining in the event of incidents. The acid vapors are collected in a cleansing system.
The analysis relates to the workman who leads this operation working station and one considers in this example only the risks suitable for this. The system was cut out, at the time of the analysis, in seven sub-systems which are:

1. - NITRIDING MIXTURE SUPPLY
2. - FOOD PRODUCES "X"
3. - AGITATION SYSTEM
4. - COOLING
5. - SYSTEM OF CONNECTION BETWEEN ENGINES
6. - DRAINAGE SLUICES FAST
7. - ASPIRATION OF ACID VAPORS

It is then carried out to the establishment of the analysis of the mode of failure.

GENERAL DIAGRAM OF THE NITRATION OF PRODUCT "X"