Intelligent reliability analysis

An ideal automated reliability analysis system would take a CAD model as input, then identify critical components and output failure probabilities. Unfortunately, the practical systems in use today require a fault tree/spl minus/a kind of and/or graph/spl minus/as their input. Since the cognitive distance between the CAD model and its associated fault tree is large, the manual translation step is a source of many mistakes. Furthermore, the use of fault trees makes it difficult to handle the cyclical dependencies that naturally occur among system components. The functional dependency graph, a representation midway between CAD models and fault trees, is described and methodology that automates reliability and diagnostic analyses is developed. When the resultant technology is employed, the knowledge burden is more equally shared between the user and the computer. In addition, more complicated systems can be properly analyzed because cyclical dependencies can be represented.<>