What DMA methodology is considered defensible to auditors?

A defensible methodology is agreed before the assessment starts, uses criteria and thresholds with written rationales, applies the same logic to the same kind of IRO everywhere in the assessment, uses standardised definitions across all business units, and lets any score be traced back to raw data, workshop notes, or expert input.

Assurance looks at method

Auditors won't only look at your final results. They'll examine the methodology, logic and data sources behind every decision you made. That's what limited assurance means in this context, and the revised ESRS didn't change it.

This is where most DMAs fall apart under scrutiny. The conclusions can be right and the assessment still fails. Different assessors apply different logic to the same criteria, scoring drifts, and judgement calls get made without being recorded. By the time an auditor starts pulling on threads, the inconsistencies are spread across the assessment and there's no rationale to point back to.

Four rules

Everything below assumes the first decision has already been made, which is agreeing your scoring criteria and thresholds before the assessment begins and writing down the reasoning behind each one. Changing scoring criteria partway through is survivable if it's documented. It's fatal if it isn't.

Keep a standalone methodology document. Updated as you go and ready to hand to your assurance team from the first day, rather than assembled when they ask for it.

Log every choice, especially the negative ones. The reasoning behind deciding not to report on a topic is what auditors ask about most. In an auditor's eyes, if it wasn't documented it didn't happen.

Standardise definitions across every business unit. Everyone from your internal scorers to your auditors should hold the same understanding of key terms. Where one subsidiary reads "significant" differently from another, the scores stop being comparable and the aggregate conclusion stops meaning anything.

Keep an unbroken paper trail. Every score and classification in your final results should trace directly back to raw data, workshop notes or expert input. If there's a step in the chain where the answer is "we discussed it and agreed", that step needs a record.

Clear impact wording is a methodology issue

This looks like a drafting concern. It decides how your scores come out.

Consider this impact statement, which came from a real assessment: "the company's approach to social dialogue affects employee engagement, trust in management and overall workplace harmony."

When we put it to the client's team, the room split on whether it described a positive or a negative impact. The problem is the word "affects", which is neutral in English and can be read either way.

That ambiguity carries straight through to the scores. Under the ESRS an impact is positive or negative, actual or potential, and it can't be both. Those categories are scored differently. If your scorers hold different interpretations of the same impact, their scores aren't comparable, and the aggregate is meaningless.

There are two fixes. Rewrite it so the direction is unmistakable, as in "strengthens employee engagement" or "the absence of social dialogue harms employee engagement". Or, where an impact really does work both ways, split it into two: one positive and one negative, or one actual and one potential.

Vague definitions produce vague scoring, and auditors flag vague scoring.

The judgement bar went up

The revised ESRS reduce the reporting burden. They don’t reduce the assessment effort, and they raise the demand on judgement.

A one-line justification for ruling out a topic won’t survive an auditor’s questions if the reasoning behind it was never properly worked through. Which, in our experience, is what companies expecting less work tend to have.

Kōan has worked on materiality assessments for 9 years, with companies from listed multinationals to first-time reporters across Europe, Asia and the US. If you want a second pair of eyes on your methodology before your auditor finds the gaps, get in touch.

Melina Gkiolma, Sustainability Consultant, Kōan
Published 21 October 2026 · Last reviewed 02 October 2026

Melina Gkiolma is a sustainability consultant at Kōan, specialising in CSRD and ESRS. She previously worked at Deloitte Luxembourg and is a One Young World Ambassador.