Definition
Normalisation
Adjusting scores or prices so bids are compared on the same basis.
Normalisation is the process of converting raw scores from different evaluation criteria, which may use different scales or units, onto a common basis so they can be combined into a single overall weighted score. It is most commonly applied to price scores, converting bid prices into a percentage or points figure comparable with quality marks.
Why normalisation is needed
Quality scores are often marked on a 0-5 or 0-10 scale using descriptors, while price is a monetary figure in pounds. Before these can be combined under a price-quality ratio, price must be converted (normalised) into a comparable score, typically using a formula like lowest-price-scores-maximum or a percentage-difference method.
Normalisation can also apply within quality scoring where sub-criteria use different scales, though this is less common in straightforward ITTs.
How it affects the final ranking
The choice of normalisation formula can materially change outcomes even with identical raw prices, because different formulas reward or penalise price gaps differently. A steep formula might heavily penalise a bid even slightly above the lowest price, while a gentler formula narrows the practical difference between close bids.
Bidders cannot control the formula but should understand it well enough to judge how sensitive their likely ranking is to small pricing changes before submission.
Frequently asked questions
- Is normalisation the same as price scoring?
- They overlap: price scoring is usually where normalisation is applied, converting monetary bid prices into a comparable score against quality marks. The term normalisation refers more broadly to putting different scales onto a common basis, which is most visibly done for price.
- Do I need to calculate normalisation myself before submitting?
- It is not required, but modelling it can be useful. If the ITT publishes the formula, you can estimate how your intended price is likely to score relative to an assumed competitive range, helping you sense-check your pricing strategy before submission.
- Can normalisation formulas be unfair to bidders?
- They can produce counter-intuitive results if not carefully designed, for example by disproportionately rewarding very low outlier prices. Buyers are expected to choose and disclose a formula that is transparent and applied consistently, and bidders can raise concerns through clarification questions.
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