ABSTRACT
This chapter illustrates the software fault tree analysis for the software portion of a system. It shows the failure modes effects and criticality analysis (FMECA) for a system. A fault tree analysis is illustrated on a software program that was developed to output two binary files, each of which must exist in a complete and non-corrupted form for success. Incorrect data in either of the two files may or may not cause a critical failure. The software consists of one subprogram that organizes, verifies, computes, and assembles user-entered data. Contrary to the fault tree analysis, the FMECA is performed on software from the bottom up as opposed to from the top down. The hazards are identified for the FMECA as they are for the fault tree analysis. These hazards are broken down to sub-hazards to the appropriate design level for which the FMECA is being performed on.
