The board of commissioners shall determine the powers and duties to be performed by each department and shall assign such powers and duties to each department as it may deem appropriate. The board shall prescribe the powers and duties of all officers and employees and may assign particular officers and employees to one or more departments and may require any officer or employee to perform duties in two or more departments if the work required of such officer or employee in such different departments be similar in character, and make such other rules and regulations as may be necessary or proper for the efficient and economical conduct of the business of the municipality.