Speak, Memory! Analyzing Historical Accidents to Sensitize Software Testing Novices

Accidents tend to be traumatic events that one would rather forget than remember. Software testing novices at the Vrije Universiteit in Amsterdam, on the contrary, rewind the past and learn how to safeguard the future. In this paper we will present FAIL, a rather unconventional assignment that methodically investigate 13 historical software-related accidents, varying from the Ariane-5 rocket explosion to the Knight Capital trading glitch. Innovative is that software testing students use STAMP, a modern systems-theory-based accident causality model and have the possibility to interview a witness of the famous Therac-25 radiation overexposures. A recent deployment to 96 CS graduates received positive evaluations. We learned that even a lightweight, yet systematic investigation of failures (1) motivates students, by sensitizing them to the consequences of suboptimal testing, and (2) reveals key soft-skills testers need to prevent disasters, such as defensive pessimism and a strong backbone. Other, more subtle benefits of the proposed approach include (3) really-happened, instead of artificial case-studies that increase a teacher's credibility, and (4) extraordinary test scenarios students will always remember. These results invite software engineering educators to include safety assessment elements in their curricula, and call on witnesses of software-related accidents to break the silence and share memories. Future work includes crafting a repository of heritage artifacts (narratives, videos, witness testimonies and physical replicas) to reproduce historical software-related accidents, and make it available to interested educators. Our hope is that motivated professionals will emerge, better prepared to engineer the safe software-intensive systems we all can rely on.