10. Example

Example of reliability issues: all engineers are concerned with the reliability of products or systems. For engineers, there are two major problems to be solved:

• know the survival curves of system components ;

• define the system's configuration either using its reliability network, or by constructing its fault tree;

These two processes are equivalent, and only more practical to handle in some cases by one method or the other.

Fuzzy mathematics is used to determine survival curves, whereas it is not used, except in a few cases, to study reliability networks and fault trees. We will demonstrate the use of confidence intervals or segments and fuzzy subsets for survival curves.

There are two ways of determining the life of a piece...