Code fault tree
This FTA diagram example was redesigned from the Wikipedia Commons file: Example Code Fault Tree.jpg. [commons.wikimedia.org/wiki/File:Example_Code_Fault_Tree.jpg]
"Use of Software Fault Tree Analysis.
Any SFTA must be preceded by a hazard analysis of the entire system. The information in the hazard analysis identifies those undesired events in the system that can cause serious consequences. It should be noted that in comple x systems not all hazards can be predetermined.
In this respect the technique does not claim to produce consistent results irrespective of the analyst. It is dependent on the judgment of the individual as to when to stop the process and which hazards to analyze.
The SFTA can be used at different stages of the software life cycle, beginning at the software requirements phase. At that early stage, only the bare minimum of the software will be defined, though the system will usually have a preliminary design. Only a very high-level SFTA will be able to be performed. However, as the software design progresses, and the code is developed, the SFTA can be “fleshed out” with the new information. High-level blocks can be broken down into specific components (modules, classes, methods, etc.)." [NASA Software Safety Guidebook. hq.nasa.gov/office/codeq/doctree/871913.pdf]
The FTA diagram example "Code fault tree" was created using the ConceptDraw PRO diagramming and vector drawing software extended with the Fault Tree Analysis Diagrams solution from the Engineering area of ConceptDraw Solution Park.