In PSUs, the 'Two-Bid System' commonly used in purchase procedures refers to:

The Two-Bid System is a transparent tendering process used to ensure fairness and technical compliance. Bidders submit two sealed envelopes simultaneously: one containing the technical bid (details on their capability, compliance with specifications, and methodology) and the other containing the financial bid (the commercial offer). The technical bids are opened first and evaluated. Only the financial bids of those bidders who are found to be technically qualified are opened later. This prevents the technical evaluation from being biased by the price.