Arranges it into units, showing organisation (11)
I believe the answer is:
institution
'organisation' is the definition.
(I know that organisation can be written as institution)
'arranges it into units' is the wordplay.
'arranges' indicates an anagram (I've seen 'arranging' mean this).
'it'+'into'+'units'='itintounits'
'itintounits' with letters rearranged gives 'INSTITUTION'.
'showing' is the link.
(Other definitions for institution that I've seen before include "Established law or custom" , "residential home" , "Special needs hospital" , "Large organisation; established custom" , "Established practice" .)