There are different interpretations of fairness in public procurement, so rather than define fairness as treating all bidders equally, better to mention how fairness is achieved in public procurement.
To achieve fairness in the public procurement process:
Decision–making and actions must be unbiased, and no preferential treatment should be extended to individuals or organizations given that public procurement activities are undertaken with public funds.
All offers must be considered on the basis of their compliance with the stipulations of the solicitation documents, and offers should not be rejected for reasons other than those specifically stated in the solicitation documents and the procurement rules.
A contract should only be signed with the supplier, contractor or service provider whose offer is compliant and best responds to the objectives of the requirement in terms of technical capability and price.
Suppliers, contractors or service providers should have the right to challenge the procurement process whenever they feel they were unfairly treated or that the procuring entity failed to carry out the procurement process in accordance with the public procurement rules. Such challenges must be based on the solicitation documents and/or the public procurement rules.