The commission of a joint system may create an executive committee, the composition of which must be set forth in the bylaws of the joint system. The composition of the executive committee shall afford a fair representation of the members. The executive committee may exercise such powers during intervals between the commission’s meetings as provided by the commission. The terms of office of the members of the executive committee and the method of filling vacancies must be fixed by the bylaws of the joint system. A change in membership of a joint system is not final until notice of the change is filed with the Secretary of State, except where a joint system is organized to create a financing pool.