Analysed shift duties before start of day (7)
I believe the answer is:
studied
'analysed' is the definition.
('study' can be a synonym of 'analyse')
'shift duties before start of day' is the wordplay.
'shift' is an anagram indicator.
'before' says to put letters next to each other.
'start of' indicates taking the first letters.
The initial letter of 'day' is 'd'.
'duties' is an anagram of 'studie'.
'studie'+'d'='STUDIED'
(Other definitions for studied that I've seen before include "Examined" , "Well-considered" , "Looked at closely" , "Read" , "Learnt by reading" .)