> The lesson of the Therac-25 is not writing perfect software I will guess that the author will agree with you. The goal is a safe solution and that implies be

> The lesson of the Therac-25 is not writing perfect software I will guess that the author will agree with you. The goal is a safe solution and that implies better software, better hardware, better procedures, ... anything that you can learn from mistakes to make this not happen again. If you look at plane crashes reports they will highlight software and hardware malfunction but also pilot mistakes (one plane crash happened when the pilots were distracted talking during landing about another plane crash that happened because those pilots were distracted talking during landing). > The problem with the Therac-25 was NOT the race condition. Complex devices will always have bugs, That is the point of the article. " ... The reason? A race condition. An unplanned-for coincidence, made deadly by the conscious design decision to remove an old-fashioned safety interlock." The problem was the race condition. But if you solve that one, another one will pop-up. So what was deadly was the "decision to remove a safety interlock". We need to identify which one can be solved, and do it. If we can not write perfect software we should add hardware safety. If hardware safety is not enough we need to improve the procedures to handle it. If that is not good enough, we can add more software to help were humans are failing... it is a refining process that you learn studying past failures.