Haw. Rev. Stat. § 26-38
Except as otherwise provided by this chapter, every power and duty conferred by law and required to be performed by any officer, board, department, bureau, commission, administrative agency, or instrumentality of the State existing immediately prior to November 25, 1959, shall hereafter be exercised and performed by the head of the respective department established by this chapter, whether the head of the department be a single executive, board, or commission.
Except as otherwise provided by this chapter, the head of a department may assign any function vested in his department to any subordinate officer or employee as he deems desirable. With the approval of the governor, the head of a department may establish or abolish within his department any division or other administrative unit to achieve economy and efficiency and in accord with sound administrative principles and practices and procedures.
The head of each department may prescribe regulations for the administration of his department, for the conduct of its employees, for the performance of its business, and for the custody, use and preservation of records, equipment, and other property pertaining thereto; provided that the regulations shall not be inconsistent with the requirements of chapters 76, 91, and 92, or rules promulgated by the governor, or other laws of the State.
HRS § 26-38