Published 20 January 2026 by eSourcingData
Fair evaluation is the part of a tender most likely to be challenged, so it is the part worth getting right. Fairness comes from applying the same published criteria consistently to every bid, evidencing each score, and moderating as a panel. This guide covers how to structure evaluation so the outcome holds up under scrutiny.
Suppliers must know how they will be judged before they bid. Publish your award criteria, their weightings and any sub criteria in the tender documents, and do not change them once responses are in. Moving the goalposts mid process is one of the surest ways to trigger a successful challenge.
Under the Procurement Act you evaluate against the most advantageous tender, which means balancing quality, price and other factors such as social value rather than defaulting to lowest cost. Set the weightings to reflect what actually matters for the contract, and be able to explain why each weighting was chosen.
Write scoring descriptors that describe what a strong, adequate and weak answer looks like for each question. Descriptors turn a subjective judgement into a shared standard the whole panel can apply.
Each evaluator should read and score the responses on their own first, without discussing them. Independent scoring surfaces genuine differences of view, which are exactly what moderation exists to resolve. If everyone scores together from the start, one confident voice can quietly anchor the whole panel.
Ask evaluators to write a short justification against every score, tied to the evidence in the bid and the published descriptors. A number on its own proves nothing, but a number with a reasoned note behind it is defensible.
Keep pricing evaluation separate from quality where you can. Knowing a supplier is cheapest before you assess their quality answers is a well known source of unconscious bias.
Moderation is where evaluators compare independent scores and agree a single consensus figure for each answer. The aim is not to average the numbers, it is to reach a reasoned agreement grounded in the evidence. Where scores diverge, talk through why until the panel settles on a justified position.
Record the moderated score and the agreed rationale for each question. This record is the backbone of your assessment summaries and your first line of defence if a losing supplier queries the outcome. Vague notes such as good answer are worthless, specific evidence based reasoning is not.
Chair the session actively so quieter evaluators are heard and no single person dominates. A well run moderation produces better decisions, not just better paperwork.
If a price looks abnormally low, you can ask the supplier to explain how it is deliverable before drawing conclusions. A low price may reflect genuine efficiency, or it may signal a misunderstanding of the requirement that will cause problems later. Investigate rather than assume.
Correct arithmetic errors consistently and transparently, and treat all bidders the same way. If you allow one supplier to clarify an obvious slip, you must offer the same treatment to others in the equivalent position.
Do not let a strong quality answer quietly excuse a non compliant bid. If a response fails a mandatory requirement, that is a compliance judgement to make openly, not something to smooth over in scoring.
Once scores are moderated and the winner identified, issue an assessment summary to every supplier. It should explain how their bid scored against each criterion and why the winning bid was assessed as most advantageous. Clear feedback reduces challenges and improves the quality of future bids into your organisation.
Retain the complete evaluation record, from independent scores through moderated consensus to final decision. If the award is questioned during standstill or afterwards, a contemporaneous audit trail is what protects the decision.
Debrief the panel briefly on what worked. Small improvements to descriptors and process each time compound into consistently better evaluations.
Structured, evidenced evaluation with a full audit trail
eSourcingData runs independent scoring, moderation and consensus in one place, capturing every score and rationale so your award decision is transparent and defensible.
See eSourcingDataWhat does most advantageous tender mean?
Under the Procurement Act you assess the most advantageous tender, balancing quality, price and other published factors such as social value, rather than automatically awarding to the lowest price.
Should evaluators score together or separately?
Evaluators should score independently first, then meet to moderate. Independent scoring exposes genuine differences of opinion that moderation then resolves into an agreed consensus.
Can I change my criteria during evaluation?
No. Award criteria and weightings must be published in advance and applied as stated. Changing them once bids are received undermines fairness and invites challenge.
What is moderation?
Moderation is the session where evaluators compare independent scores and agree a single reasoned consensus score for each answer, recording the rationale behind it.
How do I handle a suspiciously low price?
You can ask the supplier to explain how the price is deliverable before deciding. Treat all bidders consistently when investigating pricing or correcting errors.
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