After expiration of the period stated in the announcement prescribed in Section 10000.5, the Executive Director shall evaluate statements of qualifications and performance data that have been submitted to the Authority. Discussions shall be conducted with no less than three firms regarding the required service. From the firms with which discussions are held, the Executive Director shall select no less than three, in order of preference, based upon the established criteria, that are deemed to be the most highly qualified to provide the services required. Where three firms cannot be found, that could provide the required service, a full explanation including names and addresses of firms and individuals requested to submit qualifications must be entered in the files.