4. System availability

Here are a few typical cases and, for each, how to assess availability.

Reliability reminder :

• A "series system" is one in which the failure of a single component leads to the failure of the whole system.

• A "parallel system" is a system that only fails when all its components fail.

• A "mixed system" is a system made up of series sub-assemblies connected in parallel.

• Systems that do not fall into one of the above categories are referred to as "complex".