The director, as soon as practicable after this Part takes effect in the city, shall cause to be prepared a classification plan which shall consist of classes, designated by standard titles, designed to provide for all positions in the classified service. He shall from time to time review the duties and responsibilities of the positions in the classified service and may add, combine, divide, or abolish classes, or revise the titles of existing classes. The classification plan so provided and any changes therein shall become effective when adopted hereunder as rules or amendments to rules. The director, subject to the rules, shall provide, and may amend from time to time, a written definition for each class, describing the nature of the duties and responsibilities characteristic of positions properly pertaining to the class, with illustrative examples where desirable, and setting forth the minimum qualifications requisite for entrance to positions of the class, together with the principal and natural lines of promotion. The definitions shall be descriptive only, and not restrictive. They shall be construed merely as defining the several classes, and not as prescribing what the duties or qualification requirements of any position shall be, or as limiting the right of any employee to compete for promotion.
La. R.S. § 33:2402