A software optimisation approach that uses identity, usage, and lifecycle data to decide what to keep, remove, or consolidate. It treats access and spend as linked governance problems rather than separate finance and security exercises.
Expanded Definition
Identity-led rationalisation is the practice of using identity posture, usage telemetry, and lifecycle status to decide which NHIs should be retained, reduced, merged, or retired. It is narrower than generic software portfolio rationalisation because the unit of analysis is not just an application, but the credentials, service accounts, tokens, and API keys that keep it functioning.
In NHI governance, the method sits at the intersection of security and spend control: an identity that is rarely used, overprivileged, or orphaned may be both a waste item and a risk item. That is why the concept aligns well with the control intent of NIST Cybersecurity Framework 2.0, especially when organisations need to improve visibility, protect access, and manage technical debt across machine identities. Definitions vary across vendors on whether rationalisation includes only cleanup or also consolidation of duplicate identities and secrets vaults.
The most common misapplication is treating identity-led rationalisation as a finance-only exercise, which occurs when teams remove licenses or software without first validating which NHIs still depend on the related credentials.
Examples and Use Cases
Implementing identity-led rationalisation rigorously often introduces dependency risk, requiring organisations to weigh lower attack surface and lower spend against the possibility of breaking hidden service-to-service workflows.
- A platform team reviews service accounts tied to a retired application, then consolidates duplicate identities before the next rotation cycle to reduce unnecessary access sprawl. The Top 10 NHI Issues page is a useful companion reference for the failure patterns this review is meant to catch.
- A security team identifies API keys that have not been used for 90 days and cross-checks them against application logs before decommissioning them, so that stale credentials are removed without interrupting active jobs.
- An engineering organisation maps all CI/CD secrets to owning systems and removes duplicated keys across pipelines after confirming the same workload is already covered by a federated identity path. For implementation logic, the NIST Cybersecurity Framework 2.0 helps anchor visibility and access governance.
- During cloud cost reviews, a team flags an NHI attached to an abandoned microservice and discovers the workload is still alive only because a legacy batch job is calling it, which prevents a blind cleanup action.
These decisions are easier when teams also study real-world failure patterns such as the 52 NHI Breaches Analysis, which shows how overlooked machine identities often persist long after the business process they support has changed.
Why It Matters in NHI Security
Identity-led rationalisation matters because excess NHIs are rarely neutral. An unused or duplicate service identity can still carry permissions, secrets, trust relationships, and vendor exposure, even when nobody remembers why it exists. That combination creates a compounding governance problem: the longer identities remain in circulation, the harder it becomes to prove ownership, justify access, and safely rotate or revoke credentials.
This is especially important in environments where NHIs already outnumber human identities by 25x to 50x, as described in the Ultimate Guide to NHIs. In that same research, only 5.7% of organisations report full visibility into their service accounts, which means rationalisation is often being attempted against an incomplete asset inventory. Without that visibility, rationalisation can become guesswork rather than governance.
Practitioners should treat this term as a response to identity drift, audit findings, and unexplained access paths. Organisations typically encounter the need for identity-led rationalisation only after a breach review, cost audit, or failed offboarding exposes that stale machine identities were still active, at which point the concept becomes operationally unavoidable to address.
Standards & Framework Alignment
This section maps relevant standards and security frameworks to the operational risks and controls described in this guidance.
OWASP Non-Human Identity Top 10 address the attack and risk surface, while NIST CSF 2.0 and NIST Zero Trust (SP 800-207) set the governance and control requirements practitioners need to meet.
| Framework | Control / Reference | Relevance |
|---|---|---|
| OWASP Non-Human Identity Top 10 | NHI-01 | Covers NHI inventory, ownership, and lifecycle cleanup that rationalisation depends on. |
| NIST CSF 2.0 | ID.AM | Asset management supports deciding which identities and secrets should remain in service. |
| NIST Zero Trust (SP 800-207) | PL-6 | Zero Trust planning requires continuous validation of identity, trust, and access necessity. |
Continuously reassess machine identity trust relationships and eliminate unnecessary standing access.
