Under this system there is a county financial management committee. The committee consists of the county mayor, supervisor of highways, director of schools, and four (4) members elected by the county legislative body. The four elected members need not be members of the county legislative body. T.C.A. § 5-21-104 (b). The financial management committee establishes and approves policies, procedures, and regulations implementing a sound and efficient financial system for administering the funds of the county. T.C.A. § 5-21-104 (e). The county legislative body, by resolution, either may create the following committees or it may authorize the financial management committee to assume functions of any or all of the following special committees: (1) budget committee, (2) investment committee, and (3) purchasing committee. T.C.A. §§ 5-21-104 (e) and 5-21-105.