> Several of the [...] engineers stated their concerns about the O-rings and urged a delay, but the concerns didn't get communicated beyond the Level III Flight

> Several of the [...] engineers stated their concerns about the O-rings and urged a delay, but the concerns didn't get communicated beyond the Level III Flight Readiness Review (FRR). I think this is partially a fault of engineers, and/or the development/project model. They were not able to clearly state that no, it's a no-go, or yes, it's a go, they had "concerns". But that is probably useless. Therefore the problem is they lacked the conceptualization framework, a risk model, to state the severity of their concern, what is it based on, and someone should have been able to aggregate it and determine how this estimated risk influences the mission's overall risk. That said, it is entirely the management's fault that they lacked this critical expertise/competence to manage risk and the project, and the engineers. (And naturally some of those managers themselves were engineers.)