Obtaining Valid Safety Data for Software Safety Measurement and Process Improvement

The authors report on a preliminary case study to examine software safety risk in the early design phase of the NASA Constellation spaceflight program. Their goal is to provide NASA quality assurance managers with information regarding the ongoing state of software safety across the program. They examined 154 hazard reports created during the preliminary design phase of three major flight hardware systems within the Constellation program. Their purpose was two-fold: to quantify the relative importance of software with respect to system safety; and to identify potential risks due to incorrect application of the safety process, deficiencies in the safety process, or the lack of a defined process.