| Open Procedure | Restricted Procedure | Competitive Dialogue | Negotiated Procedure |
Possibility to limit number of bidders | No prequalification or pre-selection is permitted. Any interested company may submit a bid. | The number of bidders may be limited to no less than five in accordance with criteria specified in contract notice (prequalification and shortlisting permitted). | The number of bidders may be limited to no less than three in accordance with criteria specified in contract notice (prequalification and shortlisting permitted). | The number of bidders may be limited to no less than three in accordance with criteria specified in contract notice (prequalification and shortlisting permitted). |
Discussions during process | The specifications may not be changed during the bidding process, and no negotiations or dialogue may take place with bidders. Clarification is permitted. | The specifications may not be changed during the bidding process, and no negotiations or dialogue may take place with bidders. Clarification is permitted. | Dialogue with bidders permitted on all aspects (down-scaling bidders permitted between successive stages of the dialogue). When dialogue is concluded, final complete bids must be requested based on the solution(s) presented during the dialogue phase. | Negotiations permitted throughout process. Successive stages can be used to reduce the number of bidders (further short-listing). |
Discussions after final bid is submitted | No scope for negotiations with a bidder after bids are submitted. | No scope for negotiations with a bidder after bids are submitted. | Only permitted to clarify, fine tune or specify a bid or confirm commitments. No changes permitted to basic features. | Not relevant because the negotiations can continue until the contract is agreed. There need be no "final bid" per se. |
Basis for award | Lowest price or most economically advantageous tender. | Lowest price or most economically advantageous tender. | Most economically advantageous tender. | Lowest price or most economically advantageous tender. |