TABLE OF CONTENTS We first give out the basic notions constituting the vocabulary of fault trees before moving on to the stages of construction and treatment of fault trees (FT).
The fault tree is represented by means of three types of graphic symbols:
The logic gates or operators: fundamental operators, as given in Table 3.1 and special operators, as indicated in Table 3.2. This list is not exhaustive, as other operators are not included here.
The events, given in Table 3.3.
The transfer triangles, as given in Table 3.4.
| Graphic symbol | Name | Meaning |
|---|---|---|
| | OR | The output is generated if at least one of the inputs exists |
| | AND | The output is generated if all the inputs exist |
| Graphic symbol | Name | Meaning |
|---|---|---|
| | Exclusive OR | The output is generated if one and only one input exists |
| | Priority or sequential IF | The output is generated if all the inputs exist, with an order of appearance |
| | IF | The output is generated if the input exists and if the state C is verified |
| | K-out-of-n combination | The output is generated if k-out-of-n inputs exist (1 ? k ? n) |
| | Matrix | The output is generated for certain combinations of inputs |
| | Delay | The output is generated with a delay ?t over the input that should be present during ?t |
| | No | The output is generated when the input is not produced |
| Graphic symbol | Meaning |
|---|---|
| | Rectangle Top or intermediate event |
| | Circle |
