Search for:
Base failures that cause safety goal failures of at least two different safety goal functions.
Explanation:
Base failures will be searched for that are linked to two or more violations of safety goals. It is irrelevant for the search whether the violations of safety goals are reached via single-point fault paths or multi-point fault paths.
Example:
Abbreviations:
- The shown sample structure consists of three structure elements. Two
safety goals
each with one
violation of safety goal 
are
assigned to the root element. The other two structure elements SE and BSE have functions and failures assigned.
- In the following failure graph, you can see how the base failures BF are linked to the violations of safety goals.
- Two placeholders for the failure type are automatically assigned in the IQ Software to each violation of safety goal. That is shown in the failure graph and the failure net. If you anchor a violation of safety goal in the failure graph or the failure net these placeholders for failure types will automatically show next to the violation of safety goal in the direction of causes. The failure types tell if the failures leading to a violation of safety goal according to ISO 26262 are single-point faults or multiple-point faults.
- The considered Quality Rule (QR) detects base failures (BF), which are linked to two or more different violation of safety goals. It is irrelevant for the search whether the violations of safety goal are reached by single-point fault paths or multiple-point fault paths. The following search result is obtained from analyzing the failure graph above:
Search result:
The base failure BF1 is marked as hit.
Only BF1 is linked to both violations of safety goals TSG1 and TSG2 und thus meets the QR filter condition. All other BF are linked to only one violation of safety goal and are therefore not included in the search result.