How should security teams reduce identity-driven risk in manufacturing environments without disrupting production systems?

Start with identity controls that close the most common access gaps, especially shared credentials, weak third-party access, and inconsistent verification across IT and OT. Prioritise passwordless authentication, person-level accountability, and unified identity governance so security improves without line stoppages. In manufacturing, the goal is to reduce attacker entry points while preserving availability, reliability, and safety.

Why This Matters for Security Teams

Manufacturing environments fail differently from office IT because identity controls can interrupt production, safety systems, and vendor support if they are applied bluntly. The real risk is not just unauthorised login; it is attacker use of shared accounts, stale access, and weak third-party credentials to move from a low-trust foothold into systems that cannot tolerate downtime. That is why identity governance must be precise, observable, and designed around availability.

NHI Management Group’s Ultimate Guide to NHIs notes that 97% of NHIs carry excessive privileges, which is especially dangerous in plants where service accounts often bridge IT, OT, and remote maintenance. The NIST Cybersecurity Framework 2.0 reinforces that access governance has to be continuous, not periodic, if organisations want resilience rather than one-time compliance.

In practice, many security teams discover identity drift only after a vendor laptop, shared operator account, or unattended API key has already been used to reach a production network segment.

How It Works in Practice

The safest approach is to reduce identity-driven risk in layers, starting with the highest-friction gaps that attackers repeatedly exploit. In manufacturing, that usually means eliminating shared credentials where possible, moving privileged users and vendors to person-level authentication, and treating machine identities as first-class assets with ownership, expiry, and logging. Current guidance suggests that controls should be introduced in a way that preserves line uptime, often by starting in remote access, engineering workstations, and supporting IT systems before touching production controllers.

A practical baseline includes:

• Passwordless or phishing-resistant authentication for humans, with break-glass access reserved for true emergencies.
• Just-in-time elevation for privileged tasks so access exists only long enough to complete the work.
• Strong lifecycle controls for service accounts, API keys, and integrations, including rotation, revocation, and ownership.
• Network and identity segmentation so a vendor session cannot freely reach safety, historian, and MES layers.
• Continuous logging of who accessed what, when, from where, and under which approved change or ticket.

For third parties, the issue is often not whether access exists, but whether it is visible and bounded. The Ultimate Guide to NHIs — Key Challenges and Risks highlights how poor visibility and overprivileged access expand exposure, while NIST SP 800-53 Rev 5 Security and Privacy Controls provides a control baseline for access enforcement, auditability, and least privilege. Where possible, pair identity checks with change windows and approved maintenance workflows so authentication does not become a production bottleneck.

These controls tend to break down when legacy OT devices cannot support modern authentication, forcing security teams to wrap compensating controls around systems that were never built for per-user identity.

Common Variations and Edge Cases

Tighter identity control often increases operational overhead, requiring organisations to balance stronger assurance against the realities of plant uptime, vendor dependency, and safety certification. That tradeoff is most visible in brownfield environments, where old controllers, shared HMI accounts, and vendor-managed tooling may not support modern SSO or per-user attribution. In those cases, best practice is evolving rather than settled: compensating controls, such as jump servers, session recording, narrow time windows, and token scoping, are often used while the environment is modernised.

A second edge case is emergency access. Production teams may need immediate entry during outages, but that does not justify standing privilege. The better pattern is pre-approved break-glass accounts with strong monitoring, short expiry, and post-use review. For plants with heavy contractor reliance, identity governance should also include offboarding discipline, because dormant vendor access is a common blind spot. NHI Management Group research on 52 NHI Breaches Analysis and the Top 10 NHI Issues shows how frequently weak rotation, excessive privilege, and incomplete visibility turn into real incidents. The main exception is where a system cannot be changed without revalidation, in which case security teams should isolate it and reduce surrounding trust instead of forcing immediate replacement.

Related resources from NHI Mgmt Group

• How should security teams reduce NHI risk without breaking production systems?
• How should NHS security teams reduce privileged access risk without disrupting clinical operations?
• How should security teams reduce risk from shared secrets in identity systems?
• How should security teams reduce cloud identity risk in customer data environments?