TL;DR: Manufacturers integrating IT and OT still cite security as the main barrier, with 46% naming it the top concern, 50% relying on OT assets older than 15 years, and only 15% reporting mature cybersecurity practices, according to IDC InfoBrief sponsored by Imprivata. Legacy access, poor visibility, and misaligned priorities show that convergence fails when identity controls are bolted onto systems that were never designed for shared governance.
At a glance
What this is: This analysis examines how IT/OT convergence in manufacturing exposes weak access assumptions, especially around shared logins, legacy assets, and limited visibility.
Why it matters: It matters because IAM, PAM, and identity governance teams have to extend accountability and access control into environments that were never built for modern identity workflows.
By the numbers:
- 46% of manufacturers cite security concerns as the top barrier to IT/OT convergence.
- 50% still rely on OT assets that are 15+ years old.
- Only 15% have mature cybersecurity practices.
Context
IT/OT convergence in manufacturing brings operational systems and business systems into the same control plane. That creates an identity problem as much as a technology problem, because access models built for isolated OT estates do not automatically work when users, devices, vendors, and workflows begin to overlap.
The security gap is not abstract. Shared logins, weak visibility, and inconsistent onboarding are all symptoms of governance designed for separate environments now being asked to support shared accountability. In manufacturing, that makes access management a core control for both uptime and resilience.
Key questions
Q: Where do shared logins fail in IT/OT environments?
A: Shared logins fail when organisations need to prove who performed an action, because the same credential may be used by multiple operators, shifts, or vendors. That breaks accountability, weakens incident response, and makes access reviews unreliable. In converged manufacturing environments, the control must move from shared credential convenience to individually attributable access.
Q: Why do legacy OT assets make IT/OT convergence harder to secure?
A: Older OT systems were not designed for modern identity governance, so they often lack individual attribution, central logging, or flexible access controls. That means security teams must govern risk around systems that cannot easily prove who accessed them, which increases audit gaps and incident response uncertainty.
Q: What breaks when IT and OT teams do not align on access policy?
A: When IT prioritises tighter security and OT prioritises uptime, organisations often default to broader access, inconsistent approvals, and exception-driven workarounds. The result is privilege creep that spreads across engineers, contractors, and support teams. Effective convergence requires access design that protects production without turning every operational task into a manual exception.
Q: How should manufacturers govern third-party access in converged IT/OT environments?
A: Treat vendor access as task-scoped access, not a standing support pathway. Limit it to the specific system, short duration and approved session needed for the job, then monitor activity and remove access when the task ends. This reduces the chance that remote support becomes an uncontrolled route into production.
Technical breakdown
Shared logins break accountability in legacy OT
Legacy OT environments often rely on shared credentials because the systems were built before modern identity controls were routine. That means the system can record that access occurred, but not who actually used it, which weakens forensic value, recertification, and incident response. In IT/OT convergence, this is not just an authentication problem. It is a governance problem because operational access becomes hard to trace across shifts, vendors, and mixed trust zones. Badge plus PIN or individual authentication methods restore attribution without forcing every system into a purely IT pattern.
Practical implication: Replace shared access with individual authentication so every operator action can be tied to a person or accountable account.
Visibility gaps hide third-party and insider access
Manufacturing sites often cannot consistently see who accessed which asset, when, and from where. That matters because legacy equipment may have limited telemetry, while third-party vendors may interact with sensitive systems across maintenance, support, or integration work. Without unified access logs, organisations lose the ability to detect misuse, confirm least privilege, or prove what happened during an incident. In converged IT/OT environments, visibility has to extend beyond endpoints and cloud tools into the operational layer itself.
Practical implication: Centralise access logging across IT and OT so audits, vendor oversight, and incident response can rely on the same evidence set.
Least privilege becomes harder when uptime and efficiency compete
IT and OT teams optimise for different outcomes, which is why access policy drifts when integration projects move too quickly. OT teams often resist controls that appear to threaten uptime, while IT teams push for tighter security and standardisation. The result is usually broader access than intended, especially for engineers, contractors, and support teams who need operational flexibility. Least privilege in this setting is not just a policy statement. It depends on workflow design, approval boundaries, and access methods that do not force the business to choose between productivity and control.
Practical implication: Design access paths that keep privilege narrow without interrupting production workflows or maintenance operations.
Threat narrative
Attacker objective: The objective is to move through manufacturing environments without clear attribution, gaining access that is difficult to detect, investigate, or contain.
- Entry often begins with shared logins, inconsistent onboarding, or vendor access paths that are valid across multiple operational systems.
- Escalation occurs when those credentials are reused across legacy assets that lack individual attribution and modern access boundaries.
- Impact shows up as weak audit trails, reduced ability to detect misuse, and broader exposure when an attacker or insider blends into routine plant activity.
Breaches seen in the wild
- tj-actions/changed-files compromise 2025: A stolen bot token let attackers poison tj-actions/changed-files so pipelines printed their CI/CD secrets to public logs (CVE-2025-30066).
- reviewdog Action compromise 2025: A stolen maintainer token poisoned reviewdog/action-setup, leaking CI secrets including the tj-actions bot token used in the next attack.
Read and download The State of NHI & AI Agent Breach Report 2026, covering 150+ breaches impacting Non-Human Identities including AI Agents.
NHI Mgmt Group analysis
Shared login environments create an accountability gap, not just an authentication gap. When one credential is used by multiple operators, the governance model can no longer distinguish ownership, timing, or intent. That breaks recertification, auditability, and incident attribution at the same time. The practitioner implication is that identity must remain individually attributable even when operations are shared.
IT/OT convergence exposes an identity model mismatch. IT access controls assume frequent change, centralized management, and modern telemetry, while many OT systems were designed for stability and isolation. The article’s 15+ year asset figure shows why bolting modern IAM onto old environments produces uneven coverage. Practitioners should treat converged access as a cross-domain governance problem, not a tooling upgrade.
Visibility is the control that determines whether OT security can scale beyond local teams. If you cannot see who accessed a device, a vendor session, or a plant asset, you cannot apply least privilege with confidence. The named concept here is the identity visibility gap: access exists, but the organisation cannot consistently prove how it was used. That gap becomes more damaging as supply chain partners and remote support enter the picture.
Security and uptime are not competing control sets, but they do require different access design choices. Manufacturing teams often frame OT security as a trade-off against production continuity, yet the article shows that poor access design creates both friction and exposure. The right conclusion is not to relax governance, but to make access paths operationally usable enough that users do not bypass them. That is where modern identity governance earns its value.
Convergence shifts identity from a user-management issue to an operational resilience issue. Once IT and OT share workflows, a weakness in access control can interrupt maintenance, delay onboarding, and obscure incident reconstruction. That means IAM, PAM, and recertification decisions now influence plant resilience directly. Practitioners should manage converged access as part of operational risk, not as a separate security project.
From our research library:
- 92% of organisations expose NHIs to third parties, raising concerns about supply chain security, according to the Ultimate Guide to NHIs.
- Read next: OT and ICS Identity and Access Guide
What this signals
Identity visibility gap: Converged plants need access evidence that spans operators, vendors, and devices, because shared credentials and local exceptions erase the traceability IAM depends on. Once that evidence disappears, recertification becomes an administrative exercise instead of a control.
Manufacturing teams should expect IT/OT convergence to pull PAM, SSO, and recertification into operational workflows. Access control that works only on the IT side will not hold when maintenance, shift changes, and vendor support all touch the same environment.
For practitioners
- Replace shared operator accounts Move plant and support access to individually attributable identities, using badge plus PIN or equivalent methods where legacy systems cannot support modern authentication natively.
- Unify access logging across OT and IT Collect who accessed what, when, and where across operational systems so investigations and reviews have consistent evidence from both environments.
- Extend vendor oversight to operational access Track third-party sessions and contractor pathways separately from internal user access so maintenance and support activity does not blur accountability.
- Tie least privilege to workflow design Set access boundaries around shifts, maintenance tasks, and plant exceptions so production teams can work without defaulting to standing broad access.
- Treat legacy OT as a governance constraint Map where 15-year-plus assets cannot support modern identity controls and define compensating controls for attribution, logging, and privileged use.
Key takeaways
- IT/OT convergence fails when identity controls cannot preserve accountability across legacy operational systems and shared workflows.
- The article points to concrete exposure signals, including shared logins, 15-plus-year-old OT assets, and weak cybersecurity maturity.
- Manufacturers need access designs that keep privilege attributable, visible, and narrow without forcing the plant to trade resilience for control.
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 and MITRE ATT&CK address the attack and risk surface, while NIST SP 800-53 Rev 5 and CIS Controls v8 set the governance and control requirements practitioners need to meet.
| Framework | Control / Reference | Relevance |
|---|---|---|
| OWASP Non-Human Identity Top 10 | NHI-05 — Overprivileged NHI | Shared logins and broad plant access create over-privileged identity conditions. |
| NHI-10 — Human Use of NHI | Legacy manufacturing access often relies on shared human use of credentials and accounts. | |
| Recommendation — Map shared OT accounts and broad vendor access to NHI-05 and remove standing privilege where possible. Eliminate shared credential use and assign identity to individual operators wherever systems permit. | ||
| NIST SP 800-53 Rev 5 | AC-6 — Least Privilege | Least privilege is central to limiting access across converged IT and OT environments. |
| Recommendation — Apply AC-6 to bound operator, vendor, and maintenance access to the minimum required scope. | ||
| CIS Controls v8 | CIS-5 — Account Management | Account lifecycle and shared account governance are core weaknesses in the article. |
| Recommendation — Use CIS-5 to inventory, assign, and review plant accounts with clear ownership and lifecycle controls. | ||
| MITRE ATT&CK | TA0006;TA0008 — Credential Access; Lateral Movement | Shared credentials and flat OT access paths support credential abuse and spread across systems. |
| Recommendation — Track shared-account exposure against TA0006 and TA0008 to prioritise high-risk OT segments. | ||
Key terms
- IT/OT Convergence: The integration of enterprise information systems with industrial operations so data, users and workflows move across both environments. In manufacturing, convergence improves visibility and efficiency, but it also forces identity controls to work across systems that were historically governed very differently.
- Shared login: A single set of credentials used by more than one person or role. Shared logins reduce accountability because actions cannot be cleanly attributed to an individual, which weakens audit trails, incident response, and lifecycle governance in environments that need precise access ownership.
- Access Visibility: Access visibility is the ability to see, in one place, which identities can reach which data, applications, and services. For IAM and data security teams, it is the difference between reviewing isolated permissions and understanding real blast radius across environments.
- Least Privilege: A security principle requiring that every identity, human or non-human, is granted only the minimum permissions necessary to perform its function. Least privilege is the single most effective control for reducing NHI blast radius.
Deepen your knowledge
NHI governance, agentic AI identity, and machine identity lifecycle are core topics in our NHI Foundation Level course, the industry's only accredited NHI security programme. If you are building or maturing an IAM programme, it is worth exploring.
Published by the NHIMG editorial team on June 25, 2026.
Updated on October 8, 2026.
NHI Mgmt Group, the independent authority on Non-Human Identity, IAM, and Agentic AI security. nhimg.org