Management alternative? About time (9)
I believe the answer is:
operation
'management' is the definition.
(thesaurus)
'alternative? about time' is the wordplay.
'alternative?' becomes 'option' ('option' can be a synonym of 'alternative').
'about' indicates putting letters inside.
'time' becomes 'era' (I've seen this before).
'option' going around 'era' is 'OPERATION'.
(Other definitions for operation that I've seen before include "Manoeuvre - military action" , "Surgical or military piece of work" , "activity" , "financial transaction" , "Act of surgery" .)