Why do high approval rates not prove that access reviews are working?

Why approval rates can look healthy while access reviews fail

High approval rates are often a sign that the review is too easy to complete, not that access is correct. When reviewers are asked to approve large entitlement lists without usage evidence, ownership context, or enough time to investigate exceptions, the process rewards default approval. The metric then measures participation, not whether unnecessary access was removed.

That distinction matters because access reviews exist to challenge standing access, not to confirm that managers will rubber-stamp what they are shown. A clean dashboard can hide stale roles, inherited permissions, dormant accounts, and access that no longer matches the current job or system relationship.

Approval rates also fail as a quality signal when the review scope is too broad or too repetitive. If the same entitlements reappear every cycle, or if reviewers are not given a practical way to reject, downgrade, or delegate an item, the programme may be producing administrative closure rather than meaningful access governance.

What a review process needs to prove before you trust the numbers

To judge whether an access review is working, look for evidence that the programme changes access, not just records responses. A useful review has clear entitlement ownership, current activity or business justification, and a defined path for revocation or remediation when access is not needed. Access Reviews and Certification Guide is a practical reference for reducing review volume and closing the loop.

The strongest signal is not the approval percentage itself, but whether the process can consistently remove unnecessary access and surface exceptions. That usually requires accurate identity data, role and entitlement clarity, and enough context for the reviewer to make a real decision. IAM and IGA Basics explains why access governance depends on both the entitlement model and the review workflow.

If the review includes service accounts, applications, or automation, the standard for evidence has to be even stronger. Non-human access often looks stable in reports even when it is overprivileged or never revalidated, so the programme should distinguish human attestations from machine access governance. Privileged Access Management Guide and NHI Lifecycle Management Guide both reinforce the need to tie review outcomes to actual access removal and lifecycle control.

Why approval-heavy reviews create governance blind spots

Approval-heavy reviews tend to fail in the same ways: fatigue, poor scoping, and weak follow-through. Reviewers often approve because they recognise a team name, trust a prior role assignment, or assume someone else already validated the access. The result is that revocation never happens, or happens too late to matter.

Another blind spot is that access reviews can be detached from operational reality. If the review cycle is annual but the environment changes weekly, the review is already behind by the time it starts. That gap is where excessive permissions accumulate, especially for shared roles, service accounts, and entitlements created for temporary projects.

A well-run programme also has to account for the fact that “approved” and “justified” are not the same thing. An entitlement can be approved because the reviewer did not challenge it, because the owner was unavailable, or because the workflow made rejection cumbersome. High approval rates therefore need to be paired with remediation completion, exception tracking, and evidence that access actually changed after the review. Joiner-Mover-Leaver (JML) Guide is useful here because many stale approvals begin with failed lifecycle updates.

Practitioner Guidance

What to verify: Treat approval rate as a process metric only. Verify that a review sample includes removed entitlements, challenged exceptions, and completed remediation, not just signed-off attestations.

What to measure: Track revocation rate, exception rate, reviewer response quality, and time-to-remediate after the review closes. If approvals stay high while removals stay flat, the review is not changing access.

Common mistake: The most common error is to optimise for completion of the campaign rather than for access reduction. That usually produces clean evidence for audit and poor security outcomes in production.

Practitioner takeaway: A high approval rate is only meaningful when it is accompanied by proof that unnecessary access was identified, challenged, and actually removed.

Related resources from NHI Mgmt Group

• How should security teams run access reviews for non-human identities?
• When do NHI access reviews create more value than a one-time cleanup?
• Why do access reviews still fail even when completion rates are high?
• Why are high pass rates not enough to prove that KYC is working well?