Section 38, The Public Procurement Act, 2004

(1) The open bid proceedings may include aprequalification stage or apply a post qualification procedure prior to the award of contract. (2) The open bid may be carried out in a single stage or in two stages, but use of the two-stage method is appropriate in the circumstances outlined in subsection (3); all other methods to be selected as the circumstances require from this Part. (3) An open bid may be held in two stages in the following cases:– (a) when it is not feasible to define fully the technical or contractual aspects of the procurement to elicit competitive bids; and (b) when, because of the complex nature of the goods, works or services to be procured, the procuring entity wishes to consider various technical or contractual solutions, and to discuss with bidders about the relative merits of those variants before deciding on the final technical or contractual specifications.