The explanation is based on grounds such as the economic nature of the manufacturing or service process, the technical solutions selected, the favourable conditions available to the bidder and the originality of the work. Each ground must be supported by documentary evidence; quotations, records determining costs and sales amounts, and prices published by public bodies are used for this purpose. In practice, explanations are rejected mostly not because of errors in the calculation, but because the supporting document does not meet the form and approval requirements stipulated by the legislation.
Legal basis: Article 38 of Law No. 4734