What is FBS (Fixed-Budget Selection)?

FBS stands for Fixed-Budget Selection. It is a consultant selection method used when the budget available for an assignment is fixed in advance and disclosed to bidders in the request for proposals (RFP). Instead of letting price compete on a sliding scale, FBS fixes the money and asks which firm can deliver the best technical work without exceeding it.

The borrower, the government agency running the project, advertises the assignment, draws up a shortlist of firms, and issues the RFP with terms of reference (ToR) that states the available budget. Each shortlisted firm submits a technical proposal and a financial proposal in separate sealed envelopes, and any financial proposal above the stated budget is rejected before the technical ranking decides the winner.

1. The borrower defines the assignment and sets a realistic fixed budget for it.
2. The assignment is advertised, firms submit expressions of interest (EOI), and a shortlist is drawn up.
3. The shortlisted firms receive the RFP, which discloses the fixed budget alongside the terms of reference and the evaluation criteria.
4. Each firm submits a technical proposal and a financial proposal in separate sealed envelopes.
5. The technical proposals are evaluated and scored first, against a minimum qualifying score, before any prices are opened.
6. The financial proposals are opened publicly, and any proposal that exceeds the fixed budget is rejected.
7. Among the proposals that clear the technical threshold and stay within the budget, the firm with the highest technical score is invited to negotiate the contract.

FBS turns the budget into a hard ceiling rather than a competitive variable. Because the amount is published, every firm designs its proposal around the same sum, so the contest is about the quality of the work delivered for that fixed budget, not about who can quote the lowest price.

The technical score reflects the firm’s experience, its methodology, and the qualifications of the proposed experts, and it must clear the minimum qualifying score stated in the RFP. Price is not scored on a sliding scale as it is in QCBS; it only has to fit inside the budget. A proposal even slightly over the ceiling is rejected no matter how strong its technical content.

The realistic risk in FBS is a budget that is too tight for the terms of reference. Read the ToR against the disclosed budget carefully before you commit. If the scope cannot be delivered for the money, reflect that in your methodology and staffing rather than promising work the budget cannot fund.

FBS suits assignments where the budget is genuinely fixed, for example capped by the financing available, and where the scope is defined precisely enough that firms can plan realistic work within that amount.

• The World Bank lists Fixed-Budget Selection among the consultant selection methods in its Procurement Framework, for assignments where the budget is fixed and can be disclosed.
• The Asian Development Bank and other multilateral development banks use FBS for well-defined assignments with a firm budget ceiling.
• It works best when the terms of reference are clear and stable, so that the fixed budget is a realistic constraint rather than a guess.

• Design the strongest technical proposal that fits inside the disclosed budget, because the highest technical score within budget wins.
• Never exceed the fixed budget; a financial proposal above the ceiling is rejected regardless of technical quality.
• Do not simply underspend, because quoting well below the budget wins nothing on its own; use the available money to raise technical quality.
• Clear the minimum qualifying technical score, or your proposal is eliminated before the budget check even matters.
• Match your proposed experts and methodology to the evaluation criteria, and size the work to what the fixed budget can realistically fund.

FBS, QCBS, and LCS all evaluate technical quality first, but they treat price very differently, and the method that applies is stated in the RFP.

• QCBS (Quality- and Cost-Based Selection) scores price on a sliding scale and combines it with the technical score using published weights, so a lower price improves the combined ranking; the budget is usually not disclosed.
• LCS (Least-Cost Selection) sets a minimum technical threshold and then selects the lowest price among the firms that pass, so cost decides the winner above the quality bar.
• FBS discloses a fixed budget, treats price as a simple check for staying within budget, and selects the highest technical score among the proposals that fit, so quality decides the winner within a fixed amount.