Zero Trust started in the world of IT. The core idea is simple. Never trust by default. Always verify. In recent years, manufacturers have discovered that the same approach belongs at the facility door and at every interior checkpoint. When people, vehicles, contractors, and vendors move through a plant, context changes constantly. Shift schedules change. Projects start and end. Equipment goes into maintenance. A static badge list is not enough.

This article explains what Zero Trust looks like for physical access control in manufacturing, how to design it, and which metrics prove it works.

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What Zero Trust means for physical access

In IT, Zero Trust evaluates identity, device health, and context before granting access to a network resource. In a plant, the resource is a door, gate, cage, control room, or hazardous zone. Zero Trust for facilities asks three questions every time a person requests entry.

  1. Who is the person and are they authenticated

  2. What is the context at this moment

  3. Does policy allow this access right now

If the answer to any of those is uncertain, access is denied or stepped up with additional checks.

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Key principles that translate from IT to the plant floor

Least privilege by role
Grant the minimum access required for each role. A maintenance tech can enter the compressor yard during an active work order but not the R and D lab.

Continuous verification
Permissions are not permanent. They adjust with shifts, projects, certifications, and environmental conditions.

Assume breach
Design interior layers. If an outer door is propped or tailgated, interior checkpoints, cameras, and intercoms limit lateral movement.

Strong identity
Pair a credential with another factor when risk is higher. Example combinations include badge plus mobile approval, badge plus PIN at night, or badge plus supervisor authorization during chemical handling.

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How Zero Trust looks at the door

Context aware rules
Access policies consider time of day, shift schedule, zone status, and environmental sensors. If air quality is unsafe, entry to that zone is blocked. If the line is shut down, contractor access requires a work order.

Dynamic permissions
Temporary access expires automatically at midnight or at the end of a project. No more lingering privileges.

Granular zoning
Break large buildings into logical zones such as production lines, tool cribs, control rooms, tank farms, and roof access. Tie each zone to a risk level and appropriate authentication.

Event driven video verification
When rules are tripped, nearby cameras pop to the top of the monitoring view. Operators see the door, the person, and the event in real time.

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Building a Zero Trust access control stack

Identity and credentialing
Use a single directory to manage employees, contractors, and vendors across sites. Sync HR status to access rights so offboarding closes badges everywhere.

Policy engine
Adopt an access control platform that supports schedules, roles, zones, and environmental inputs. Policies should be readable and auditable.

Multi factor for higher risk
Enable step up authentication during sensitive windows. Examples include after hours entries, server rooms, chemical storage, and control rooms.

Sensors and context
Integrate with fire panels, gas detection, door prop alarms, interlocks, and machine status. Context should influence the decision at the reader.

Video and intercom
Pair readers with cameras and two way audio for rapid verification and voice guidance at problem doors.

Audit and reporting
Centralize access logs, video bookmarks, and alert history. Store event trails in a way that supports OSHA, ISO, CMMC, or insurance reviews.

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Implementation roadmap for manufacturers

  1. Map risk and zones
    List doors and areas by risk level. Identify where multi factor or human verification is required.

  2. Standardize roles
    Define role based access for operators, maintenance, quality, IT, EHS, vendors, and visitors. Keep it simple. Fewer roles are easier to maintain.

  3. Connect identity to HR
    Automate onboarding and offboarding. Tie certifications to zone access. If a certification expires, access ends.

  4. Introduce context
    Feed air quality, fire, intrusion, and equipment status into the policy engine. Deny access when conditions are unsafe.

  5. Pilot step up authentication
    Start with two or three high risk doors. Measure false rejects and tune policies before wider rollout.

  6. Train and communicate
    Explain why some doors now ask for a second factor. Emphasize safety, compliance, and protection of production uptime.

  7. Measure and iterate
    Review metrics monthly. Remove unused privileges. Tighten rules where incidents cluster.

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Avoid common pitfalls

Too many roles
If every exception becomes a new role, the system will sprawl. Use temporary access with expiration instead.

All doors treated the same
Risk varies. Loading dock doors and server rooms need different controls than breakrooms.

No temporary workflows
Auditors, project teams, and OEM technicians need access that starts and ends cleanly. Build those flows into the system.

No playbook for exceptions
Decide ahead of time who approves emergency access, how to verify identity, and how to document the event.

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What to measure to prove value

  • Unauthorized access attempts by zone

  • Door prop and tailgating incidents and response time

  • Expired certifications that blocked access

  • Mean time to revoke privileges after role change

  • Audit findings tied to access control

  • Production downtime avoided due to prevented access to restricted zones

These metrics demonstrate risk reduction and support budget conversations about plant surveillance systems and factory access control.

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How this supports cybersecurity and compliance

Zero Trust at the door protects IT and OT assets by limiting who can physically reach network rooms, control cabinets, and engineering workstations. It also creates clean, exportable logs that help with CMMC, NIST, ISO 27001, ISO 45001, and customer audits that demand proof of physical controls.

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Where SSP fits

Manufacturers often have pieces of this already. Badges at the front gate. Cameras on the dock. Intercoms at the control room. SSP helps tie these together into a policy driven system that uses identity, video, sensors, and schedules to make better decisions at each door. The result is consistent access across sites, stronger worker safety, and fewer surprises.

Learn how SSP helps manufacturers protect operations, people, and property.
Let’s map your zones and pilot Zero Trust at the doors that matter most.