Plan; arrangement (6)
I believe the answer is:
scheme
I believe this clue is a double definition.
'plan' is the first definition.
(I know that scheme is a type of plan)
'arrangement' is the second definition.
(thesaurus)
(Other definitions for scheme that I've seen before include "Connive, intrigue" , "Plan; system" , "Elaborate and systematic plan of action" , "Design" , "Lay plans" .)