I just learned the two term/phrase of the title of this article. First a definiton of the more familair term -POST MORTEM:- an examination of a dead body to determine the cause of death. 

However, this term has often been used to examine the reason of a failure of a mission or task to find the cause of the  failure and hoping to learn from the failute. But the dynamics and politics of a mission or organizational task often are in conflict with such a review. This is because an unstated purpose of POST-MORTEM is often to assign blame for the failure. and it is never politically wise to assign blame to the leader who order the mission or task in the first place. The lower rank personnel who are charged with carrying out the task successfully may know in advance the weak spot of the doomed task but are afraid to stated in advance of carrying out the task because of fear to contradict the leadsers who order the mission/task.  As a result, the innocent often shoulders the burden and became the sacrificial lamb. The term Pre-Mortem was thus born. This is an exercise BEFORE the mission or task is ordered but assumed to have failed. The discussion of the PREMORTEM is to discover what may be the possible reason or weakness of the plan. In this case, no one is to be blamed but are encouraged to speak up honestly without fear of offending anyone. Everyone works together. The Museum of Failure showcases these failures to provide visitors a fascinating learning experience. Every item provides unique insight into the risky business of innovation. Again the idea here is to learn and to avoid the trap of assigning blame. Very good idea!