CS375: Software Engineering - Ethical Software Engineering Case Study: The Therac-25

Activity Goals

The goals of this activity are:
  1. To discuss the risks inherent with poor software engineering practices and poor quality controls
  2. To apply ethical strategies to mitigate software risk

Supplemental Reading

Feel free to visit these resources for supplemental background reading material.

The Activity

Directions

Consider the activity models and answer the questions provided. First reflect on these questions on your own briefly, before discussing and comparing your thoughts with your group. Appoint one member of your group to discuss your findings with the class, and the rest of the group should help that member prepare their response. Answer each question individually from the activity, and compare with your group to prepare for our whole-class discussion. After class, think about the questions in the reflective prompt and respond to those individually in your notebook. Report out on areas of disagreement or items for which you and your group identified alternative approaches. Write down and report out questions you encountered along the way for group discussion.

Model 1: Case Study: The Therac-25

Therac 25 Malfunction 54 8 sec

Questions

  1. What was Malfunction 54? What steps reproduced Malfunction 54?
  2. What were some of the incremental steps taken by the FDA throughout the Therac-25 malfunctions? Why were these actions incremental in nature, and why did/could the FDA not take stronger action?
  3. What was an example of system analysists assigning improperly low risk probabilities to certain software failures?
  4. What technological actions might have mitigated these failures?
  5. What policy changes might have helped to raise these issues in a more timely manner?

Submission

I encourage you to submit your answers to the questions (and ask your own questions!) using the Class Activity Questions discussion board. You may also respond to questions or comments made by others, or ask follow-up questions there. Answer any reflective prompt questions in the Reflective Journal section of your OneNote Classroom personal section. You can find the link to the class notebook on the syllabus.