With regards to your question, It all depends on the Company's SOP's.
For example the company I work for have a standard SOP that after certain maintainance a test flight has to be made.
Meaning that if hydraulic system had to be serviced or replaced a test flight has to be carried out. The other day bearings from the DHC8 apparently got broken and the propellar was out of balance. They had to take the propellar out re-assemble it with the new parts and of for a test flight.
my 2 cents..
Bowie.