(a) The department shall be organized and shall function as a single state agency for administrative purposes including, but not limited to, for the purposes of the accounting and financial system of the commonwealth. The secretary shall, notwithstanding any general or special law to the contrary, identify and consolidate administrative activities and functions common to the separate offices, and divisions within the department and may designate such functions 'core administrative functions' in order to improve administrative efficiency and preserve fiscal resources; provided, however, that common functions that shall be designated core administrative functions shall include, but shall not be limited to, human resources, financial management, legal, procurement, asset management, and, subject to the approval of the executive office of technology services and security, information technology. All employees performing functions so designated shall be employed directly by the secretary. The department may enter into agreements under section 22A and 22B of chapter 7 and in all respects not governed by general or special laws expressly made applicable to the department shall adhere to good business practices to be determined by the department in its procurement of equipment, materials, property, supplies and services.