The Director of Administrative Services may, at the direction of the Governor, make further inquiry and investigation as to any item requested. He shall compile the requests of the different departments, offices, institutions and expending agencies of the state into a consolidated budget, together with his recommendation as to each item contained in the budget, and shall file the same with the Governor not later than November 15 preceding the convening of the regular session of the Legislature. He shall file with the Governor also all supporting schedules and written explanations furnished by the different agencies of the state.