Basis of Selection (BOS)

The Basis of Selection determines how your bid gets evaluated and ultimately who wins the contract. Think of it as the rulebook that procurement officers must follow when choosing between competing proposals—whether they're looking for the cheapest option, the best technical solution within budget, or some combination of price and quality.

How It Works

According to the Office of the Procurement Ombud, the Contracting Policy defines "best value" as the combination of price, technical merit, and quality—determined before the solicitation goes out. The methodology must be clearly stated upfront in your solicitation documents. You can't change the rules halfway through.

Federal departments use several common selection methods in practice. Lowest evaluated price is straightforward—the compliant bid with the lowest price wins. Done. But many technical procurements use a highest combined rating approach, where you might weight technical merit at 70% and price at 30%. The guidance for supply arrangement requirements also references "lowest evaluated price per point," where bidders' scores are divided by their price to find the best value.

The Directive on the Management of Procurement emphasizes that you should limit mandatory technical criteria to essential requirements only. This ties directly to your selection method—if you declare something mandatory, any bid that fails to meet it gets eliminated before you even look at your basis of selection scoring. Then your stated methodology takes over for the compliant bids that remain.

Key Considerations

• The selection method must be documented in your solicitation before you receive any bids. You can't look at what came in and then decide how to evaluate them. This requirement for transparency appears throughout the Government of Canada Supply Manual and related procurement policies.

• Different departments have varying thresholds for when competitive bidding becomes mandatory, which affects when your basis of selection even matters. Some require competition for purchases over $15,000, others set the bar at $25,000. Below these thresholds, you might use non-competitive approaches where selection methodology is simpler or unnecessary.

• Your evaluation criteria and your basis of selection work together but aren't the same thing. Criteria define what you're assessing (experience, methodology, price). The basis of selection defines how you'll use those assessments to pick a winner.

• Whatever method you choose gets scrutinized during bid challenges. The Procurement Ombud reviews whether contracting authorities actually applied their stated methodology consistently to all bidders. Any deviation opens you up to complaints and potential re-evaluations.

Related Terms

Evaluation Criteria, Mandatory Requirements, Rated Requirements, Best Value

Sources

• Government of Canada Supply Manual - Official federal procurement policy and procedures

• Directive on the Management of Procurement - Treasury Board of Canada Secretariat

• Best Value in Procurement - Office of the Procurement Ombud

Bottom line: get your selection methodology right in the planning stage and document it clearly. Your evaluators, your bidders, and any future review processes will all hold you to exactly what you published.