Allowing no deviation from a standard (8)
I believe the answer is:
rigorous
'allowing no deviation from a standard' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for rigorous that I've seen before include "Painstakingly careful and accurate" , "Severe, precise" , "Exhaustively accurate" , "Rigid, stringent" , "firm" .)