All statements and estimates of expenditures submitted to the Office in connection with the preparation of a State budget, and any other estimates of expenditures, supporting requests for appropriations, shall be formulated according to the various functions and activities for which the respective department, office or institution of the State government (including the elective officers in the executive department and including the University of Illinois and the judicial department) is responsible. All such statements and estimates of expenditures relating to a particular function or activity shall be further formulated or subject to analysis in accordance with the following classification of objects:
20 ILCS 3005/7