A brilliant investigation and a perfunctory one converge on the same three weak fixes. The analysis explains the last failure. Only the tracker, and the engineering it forces, gets a vote on the next one. In 2017, a team of patient-safety researchers led by Kathryn Kellogg published a study in BMJ Quality & Safety with a title that asks the question this essay is about: “Our current approach to root cause analysis: is it contributing to our failure to improve patient safety?” They h...