Is there a single word descriptor for a plan, document, or process that is formalized only after its execution?
Solution 1:
Consider retrospective:
1a(1): of, relating to, or given to retrospection
Merriam-Webster
And retrospection is:
: the act or process or an instance of surveying the past
Merriam-Webster
Solution 2:
The Latin phrase post hoc is used in English as if it were a single word. Its meaning is
occurring or done after the event, especially with reference to the fallacious assumption that the occurrence in question has a logical relationship with the event it follows.
[source: Lexico]