ABSTRACT
First of all, top functions have to be defined. Hence top malfunctions are generated. In the simplest case top malfunctions are the negation of the top functions. Step 1 also includes that each of these top malfunctions have to be assigned to one of the four interception classes according to (VDA3-1 2000). To get information about possible components of the system, step 2 deals with functional relations. A tool named ‘‘Situation-based Qualitative Modeling and Analysis’’ (SQMA) allows to generate a risk estimation. Detailed information can be found in chapter 2.2. Beside weak spots, which are detected in the risk estimation, data is important for the quantitative reliability consideration. Depending on the collected reliability data from step 4, one has to decide if a quantitative or a qualitative analysis or both of them is profitable (step 5a and 5b). A matching between the two analyses can be done next. The recent step includes the variance comparison between the given reliability target values and the determined ones. If the target values do not meet the determined values, a reliability improvement can be started.
