A public agency opens a tendering process for a road building project that lasts approximately...

A public agency opens a tendering process for a road building project that lasts approximately 1 year. They post their requirements on public journal and receive some interests. After conducting due diligence process and selecting the lowest bidder, the project commences. However, the supplier complains that price of material increases because of a shortage of supply, then they demands an 5% uptick in contract value. The agency investigates the increment and sees that there is indeed a fluctuation in prices of supplier's input. They are likely to accept the proposal, but they are also concerned that supplier may demand more. To avoid making another concession with the supplier, which of the following should be a priority action of the agency?