Security teams should govern machine identities like operational actors, not passive accounts. That means assigning ownership, limiting scope, setting expiry conditions, and defining who can intervene when behaviour changes unexpectedly. In manufacturing, the control objective is not only preventing misuse, but preserving safe and timely response options when automation affects production.
Why This Matters for Security Teams
Manufacturing machine identities are not just access accounts, they are operational actors that can start jobs, trigger PLC workflows, read sensor data, call APIs, and move from IT into OT if their scope is too broad. That is why governance has to focus on ownership, purpose, expiry, and intervention rights, not just password policy. The Top 10 NHI Issues highlights how often weak lifecycle discipline shows up as exposure, while NIST Cybersecurity Framework 2.0 reinforces that identity governance must be tied to continuous asset understanding, protection, detection, and response.
In manufacturing, a machine identity that outlives a production line change, a vendor visit, or a maintenance window can become the easiest route to unauthorized commands. Current guidance suggests treating each identity as a bounded workload with a named owner and a defined shutdown path, because “shared” service accounts and permanent credentials make incident containment slow and ambiguous. Teams also need to account for operational safety: revocation must be fast, but not so blunt that it halts legitimate automation without a fallback path.
In practice, many security teams encounter excessive machine-identity privilege only after a line disruption, not through intentional review.
How It Works in Practice
Effective governance starts with an inventory of every machine identity across MES, SCADA, robotics, IoT gateways, and integration middleware, then classifying each one by business function and blast radius. From there, assign a business and technical owner, define the allowed systems and commands, and require an expiry condition tied to a project, supplier contract, or maintenance interval. The lifecycle view in Ultimate Guide to NHIs — Lifecycle Processes for Managing NHIs is useful here because manufacturing environments often fail at offboarding, not initial provisioning.
Use RBAC to express coarse job boundaries, then narrow access further with PAM and JIT for privileged sessions. For example, a service account that must change PLC recipes should receive time-bound elevation only when a change ticket or orchestration event exists, and the elevation should expire automatically when the task completes. Secrets should be short-lived where possible, stored outside code, and rotated on a schedule that matches operational risk rather than convenience. The Ultimate Guide to NHIs — Regulatory and Audit Perspectives is a useful companion for proving that ownership, review, and revocation are being enforced.
- Map each identity to a machine, process, or integration, not to a team inbox.
- Use JIT for privileged actions instead of standing admin access.
- Set TTLs on tokens, certificates, and API keys, then automate renewal only when the workload is still valid.
- Monitor for command drift, unusual destinations, and authentication from unexpected subnets or suppliers.
Where possible, pair identity controls with network segmentation and ZTA so a compromised token cannot freely reach production and engineering zones. These controls tend to break down when legacy PLCs, vendor remote support, or hardcoded credentials prevent short-lived access and timely rotation.
Common Variations and Edge Cases
Tighter governance often increases operational overhead, so teams must balance safer identity boundaries against uptime, vendor access, and maintenance deadlines. That tradeoff is especially visible in brownfield plants where older equipment cannot support modern token lifetimes or automated revocation. Best practice is evolving, but there is no universal standard yet for how much exception handling is acceptable in OT-heavy environments.
One common edge case is emergency access. Plants need a break-glass path, but it should be isolated, heavily logged, and reviewed after every use. Another is third-party support: the JetBrains GitHub plugin token exposure is a reminder that leaked development or integration secrets can have production impact when pipelines touch manufacturing systems. NHIMG research also shows how persistent secrets are in practice, with The State of Non-Human Identity Security reporting that lack of credential rotation is cited as the top cause of NHI-related attacks by 45% of organisations.
For plants using autonomous agents for scheduling, quality checks, or procurement, governance has to go beyond static roles. Agentic workloads need runtime policy checks, workload identity, and ephemeral credentials because their behaviour is goal-driven and less predictable than a conventional service account. In those cases, security teams should align identity decisions with the task itself, not assume a pre-approved access pattern will remain safe over time.
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 AI RMF set the governance and control requirements practitioners need to meet.
| Framework | Control / Reference | Relevance |
|---|---|---|
| OWASP Non-Human Identity Top 10 | NHI-03 | Addresses NHI credential rotation and lifecycle control in manufacturing. |
| NIST CSF 2.0 | PR.AC-4 | Supports least-privilege access management for operational identities. |
| NIST AI RMF | Useful when manufacturing uses autonomous agents that make runtime decisions. |
Rotate machine identity secrets on a fixed schedule and revoke them when the workload ends.
Related resources from NHI Mgmt Group
Deepen Your Knowledge
Reviewed and updated by the NHIMG editorial team on May 25, 2026.
NHI Mgmt Group — the #1 independent authority on Non-Human Identity, IAM, and Agentic AI security. nhimg.org
