When should organisations compare users during access reviews?

Why compare users during access reviews?

Comparing users is a fast way to test whether access still makes sense against a role, function, or peer baseline. It helps reviewers spot outliers, excessive access, and role drift without reading every entitlement in isolation. That makes review quality better when teams have many similar users and the question is not just “is this access valid?” but “is it consistent with the rest of the population?”

Comparisons are most useful when the review set is large enough that individual judgment would be slow or inconsistent, or when access patterns have already drifted away from the expected model. In that situation, peer comparison gives reviewers a practical reference point for finding exceptions that deserve explanation, such as a user whose entitlements are broader than peers in the same job family.

When access is defined by role design, certification, or segregation expectations, comparison becomes a control against silent entitlement creep. It is especially helpful when the access model is not perfectly clean, because the reviewer can compare like with like and quickly separate normal variation from unexplained deviation. That is why access review programs often pair entitlement review with role or peer analysis rather than treating each account as a standalone case.

When does comparison add the most value?

Peer comparison adds the most value when there is a stable grouping to compare against and the review question is about consistency, not just ownership. A finance analyst should not be compared with an engineer, but two analysts in the same function, region, or team often can be. The tighter the peer group, the more likely an unusual entitlement set is genuinely worth investigating.

It also matters when exceptions are common. If teams frequently grant temporary access, inherited access, or one-off privileges, a straight yes-or-no review can become rubber-stamping. Comparison gives reviewers a quicker way to ask whether the exception is truly justified or simply repeated because it became normal. That is one reason the access review and certification guide emphasises reducing review volume and focusing on risk.

Comparison is less useful when the population is too small, the job model is unstable, or access is genuinely bespoke. In those cases, peer baselines can mislead reviewers into approving access just because it looks similar to a nearby account. The practical test is whether the comparison helps explain the entitlement decision better than a direct ownership or business-need review would.

For organisations that want a broader operating model, IAM and IGA basics is the right foundation for understanding how access certification, role design, and entitlement governance fit together.

What makes a comparison trustworthy instead of misleading?

A comparison is only useful if the grouping logic is defensible. The reviewer needs a reliable basis such as job function, manager chain, business unit, location, or a defined role family, not a vague sense that two people “seem similar.” If the grouping is sloppy, the review can hide risk by normalising access that is actually excessive.

Good comparisons also depend on clean entitlement data. If one user has stale entitlements, hidden inherited permissions, or duplicated access from multiple systems, the peer view can be distorted. That is why comparison works best when it is paired with lifecycle controls, role maintenance, and regular cleanup of old access paths. A useful companion reference is the role mining and role design guide, which shows why role structure must stay manageable if reviewers are going to trust peer baselines.

Where peer comparison is used to confirm least-privilege expectations, it should support explanation, not replace it. A reviewer can use the outlier signal to ask for a business justification, but the final decision still needs ownership, context, and evidence. For mature programs, comparison is a triage tool that improves reviewer attention, not a substitute for accountability.

Risk and Threat Considerations

Peer comparison reduces the chance that access creep hides inside a normal-looking review, but it can also create false confidence if the peer baseline is wrong. If the comparison group is too broad, reviewers may approve excessive access because it appears common; if it is too narrow, they may miss a real exception because everyone in the group looks unusual.

Failure mechanism: Reviewers rely on a flawed peer set, a stale role model, or a noisy entitlement dataset, then treat similarity as proof of legitimacy. That can let overprivileged accounts, inherited access, or repeated exceptions survive certification cycles without a fresh business justification.

Impact: Weak comparisons can normalise privilege creep, preserve unnecessary access, and make it harder to detect accounts that are outliers for a reason. Over time, that increases the chance of unauthorized access, audit findings, and larger blast radius when an account is misused or compromised.

Practitioner Guidance

What to prioritise: Compare users first where a stable role, function, or peer baseline exists and where review fatigue would otherwise make judgment shallow. That is where comparison most improves decision quality.

What to verify: Check that the comparison group reflects real business similarity, not just organisational convenience. If the peer set is wrong, the review logic is wrong even when the tool output looks polished.

Common mistake: Treating “similar to peers” as an approval rule instead of an investigation trigger. Outliers should prompt explanation, not automatic denial or automatic acceptance.

Practitioner takeaway: Use peer comparison to expose exceptions, not to launder them, the control is only as strong as the quality of the peer group and the discipline of the final approval.

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?
• Should organisations treat service accounts like human users in access reviews?
• How should organisations design identity access so users can still authenticate during a cloud outage?