OT Cybersecurity for On-Site Maintenance Checklist
Why On-Site Maintenance Is a High-Risk Moment
Modern maintenance windows are high-risk moments. External engineers, vendor laptops, firmware updates and configuration changes - performed under pressure and often on live systems - create concentrated opportunity for mistakes, malware, or malicious action. Shieldworkz built a practical, IEC-aligned OT checklist that treats every maintenance event as a controllable, auditable operation so safety, availability and IP remain protected.
Download the full Shieldworkz OT Cybersecurity for On-Site Maintenance checklist - a turnkey pack covering pre-arrival checks to post-project validation (PTW integration, TCA sheep-dip, session recording, two-person rules and immutable backups). The checklist is organized into five phases: Pre-arrival, Arrival & Site Entry, Active Maintenance, Handover & Departure, and Post-Project Validation.
Why this matters now
Concentrated risk window: Vendor maintenance compresses many risky activities into short timeframes-remote access, file transfers, firmware flashes-often on safety-critical systems.
Operational sensitivity: OT systems can’t be treated like IT: availability and deterministic behavior are paramount; a misguided scan or untested patch can stop production or endanger lives.
Regulatory & evidentiary needs: Regulators and insurers expect auditable practices that demonstrate process safety was preserved during maintenance. The checklist embeds IEC/62443 controls to help you meet those expectations.
Why you should download this checklist
This is a hands-on instrument, not a whitepaper. It’s formatted to drop into your Permit-to-Work (PTW) process and daily operations:
Phase-by-phase controls: pre-arrival vendor vetting, arrival checks, active maintenance rules, handover validation, and post-project audit.
Operational templates: vendor manifest, TCA (sheep-dip) scan form, jump-host checklist, backup & rollback verification, PTW signoff templates.
Safety-first enforcement: two-person integrity for safety changes, LOTO integration, no-touch lists for SIS/ESD unless explicitly in scope.
Standards mapping: aligned to accepted OT guidance and security standards so you can show auditors how controls meet recognized expectations.
Quick wins + roadmap: implement immediate controls in days and mature to advanced protections (PKI, immutable backups, continuous behavioral analytics).
If you’re responsible for OT availability, safety, procurement or compliance in energy, manufacturing, chemical, pharmaceutical or utilities, this checklist gives you the operational rigour you need without stopping production.
Key takeaways from the checklist
Require a tool manifest and TCA scan before any OT connection. No exceptions.
Replace standing vendor VPNs with jump-hosts and time-boxed accounts. Record every session.
Create a mandatory last-known-good backup and verify restore in a non-production testbed before making changes.
Enforce two-person verification for any safety-affecting changes to SIS/ESD logic.
Disable wireless and cameras at BIOS/UEFI level where possible; store personal devices outside OT zones.
Log and centralize all activity during maintenance windows and review immediately after work completes.
These steps reduce the most common root causes of vendor-related incidents with minimal operational overhead.
How Shieldworkz helps you operationalize the checklist
Shieldworkz turns the checklist into capability quickly and safely:
Discovery & Pilot (7-14 days): passive mapping of maintenance touchpoints and identification of high-risk assets used in vendor interventions.
PTW & Policy Integration: tailor the checklist to your existing Permit-to-Work, LOTO and safety governance; produce sign-off matrices and approval workflows.
Sheep-Dip & Tooling Implementation: design and operate a TCA inspection station, create offline AV update processes and seed a trusted tool whitelist.
Jump-Host & Session Recording: deploy bastion architecture with MFA, just-in-time credentials, session capture and audit pipelines.
Backup & Recovery Validation: implement immutable/air-gapped backups, test restore procedures, and document RTO/RPO metrics.
Training & Exercises: role-based training for vendors, escorts and engineers plus tabletop and live drills covering emergency rollback and insider scenarios.
Operational Monitoring: enhanced surveillance during maintenance windows-behavioral baselining tuned to maintenance activities to catch anomalies quickly.
Deliverables: PTW templates, TCA SOP, bastion configuration pack, backup/restore scripts, training materials, a site-specific 90-day roadmap, and a leadership dashboard showing KPIs (inventory coverage, vendor session recording rate, MTTD for maintenance anomalies).
Take action now
Download the OT Cybersecurity for On-Site Maintenance checklist to receive the complete five-phase playbook, templates and an implementation starter plan. Fill out the form to get the checklist and schedule a complimentary 30-minute scoping call with a Shieldworkz OT specialist - we’ll help you identify high-impact pilots and create a non-disruptive implementation plan.
Download your copy today!
Get our free OT Cybersecurity for On-Site Maintenance Checklist and make sure you’re covering every critical control in your industrial network
Why On-Site Maintenance Is a High-Risk Moment
Modern maintenance windows are high-risk moments. External engineers, vendor laptops, firmware updates and configuration changes - performed under pressure and often on live systems - create concentrated opportunity for mistakes, malware, or malicious action. Shieldworkz built a practical, IEC-aligned OT checklist that treats every maintenance event as a controllable, auditable operation so safety, availability and IP remain protected.
Download the full Shieldworkz OT Cybersecurity for On-Site Maintenance checklist - a turnkey pack covering pre-arrival checks to post-project validation (PTW integration, TCA sheep-dip, session recording, two-person rules and immutable backups). The checklist is organized into five phases: Pre-arrival, Arrival & Site Entry, Active Maintenance, Handover & Departure, and Post-Project Validation.
Why this matters now
Concentrated risk window: Vendor maintenance compresses many risky activities into short timeframes-remote access, file transfers, firmware flashes-often on safety-critical systems.
Operational sensitivity: OT systems can’t be treated like IT: availability and deterministic behavior are paramount; a misguided scan or untested patch can stop production or endanger lives.
Regulatory & evidentiary needs: Regulators and insurers expect auditable practices that demonstrate process safety was preserved during maintenance. The checklist embeds IEC/62443 controls to help you meet those expectations.
Why you should download this checklist
This is a hands-on instrument, not a whitepaper. It’s formatted to drop into your Permit-to-Work (PTW) process and daily operations:
Phase-by-phase controls: pre-arrival vendor vetting, arrival checks, active maintenance rules, handover validation, and post-project audit.
Operational templates: vendor manifest, TCA (sheep-dip) scan form, jump-host checklist, backup & rollback verification, PTW signoff templates.
Safety-first enforcement: two-person integrity for safety changes, LOTO integration, no-touch lists for SIS/ESD unless explicitly in scope.
Standards mapping: aligned to accepted OT guidance and security standards so you can show auditors how controls meet recognized expectations.
Quick wins + roadmap: implement immediate controls in days and mature to advanced protections (PKI, immutable backups, continuous behavioral analytics).
If you’re responsible for OT availability, safety, procurement or compliance in energy, manufacturing, chemical, pharmaceutical or utilities, this checklist gives you the operational rigour you need without stopping production.
Key takeaways from the checklist
Require a tool manifest and TCA scan before any OT connection. No exceptions.
Replace standing vendor VPNs with jump-hosts and time-boxed accounts. Record every session.
Create a mandatory last-known-good backup and verify restore in a non-production testbed before making changes.
Enforce two-person verification for any safety-affecting changes to SIS/ESD logic.
Disable wireless and cameras at BIOS/UEFI level where possible; store personal devices outside OT zones.
Log and centralize all activity during maintenance windows and review immediately after work completes.
These steps reduce the most common root causes of vendor-related incidents with minimal operational overhead.
How Shieldworkz helps you operationalize the checklist
Shieldworkz turns the checklist into capability quickly and safely:
Discovery & Pilot (7-14 days): passive mapping of maintenance touchpoints and identification of high-risk assets used in vendor interventions.
PTW & Policy Integration: tailor the checklist to your existing Permit-to-Work, LOTO and safety governance; produce sign-off matrices and approval workflows.
Sheep-Dip & Tooling Implementation: design and operate a TCA inspection station, create offline AV update processes and seed a trusted tool whitelist.
Jump-Host & Session Recording: deploy bastion architecture with MFA, just-in-time credentials, session capture and audit pipelines.
Backup & Recovery Validation: implement immutable/air-gapped backups, test restore procedures, and document RTO/RPO metrics.
Training & Exercises: role-based training for vendors, escorts and engineers plus tabletop and live drills covering emergency rollback and insider scenarios.
Operational Monitoring: enhanced surveillance during maintenance windows-behavioral baselining tuned to maintenance activities to catch anomalies quickly.
Deliverables: PTW templates, TCA SOP, bastion configuration pack, backup/restore scripts, training materials, a site-specific 90-day roadmap, and a leadership dashboard showing KPIs (inventory coverage, vendor session recording rate, MTTD for maintenance anomalies).
Take action now
Download the OT Cybersecurity for On-Site Maintenance checklist to receive the complete five-phase playbook, templates and an implementation starter plan. Fill out the form to get the checklist and schedule a complimentary 30-minute scoping call with a Shieldworkz OT specialist - we’ll help you identify high-impact pilots and create a non-disruptive implementation plan.
Download your copy today!
Get our free OT Cybersecurity for On-Site Maintenance Checklist and make sure you’re covering every critical control in your industrial network
Why On-Site Maintenance Is a High-Risk Moment
Modern maintenance windows are high-risk moments. External engineers, vendor laptops, firmware updates and configuration changes - performed under pressure and often on live systems - create concentrated opportunity for mistakes, malware, or malicious action. Shieldworkz built a practical, IEC-aligned OT checklist that treats every maintenance event as a controllable, auditable operation so safety, availability and IP remain protected.
Download the full Shieldworkz OT Cybersecurity for On-Site Maintenance checklist - a turnkey pack covering pre-arrival checks to post-project validation (PTW integration, TCA sheep-dip, session recording, two-person rules and immutable backups). The checklist is organized into five phases: Pre-arrival, Arrival & Site Entry, Active Maintenance, Handover & Departure, and Post-Project Validation.
Why this matters now
Concentrated risk window: Vendor maintenance compresses many risky activities into short timeframes-remote access, file transfers, firmware flashes-often on safety-critical systems.
Operational sensitivity: OT systems can’t be treated like IT: availability and deterministic behavior are paramount; a misguided scan or untested patch can stop production or endanger lives.
Regulatory & evidentiary needs: Regulators and insurers expect auditable practices that demonstrate process safety was preserved during maintenance. The checklist embeds IEC/62443 controls to help you meet those expectations.
Why you should download this checklist
This is a hands-on instrument, not a whitepaper. It’s formatted to drop into your Permit-to-Work (PTW) process and daily operations:
Phase-by-phase controls: pre-arrival vendor vetting, arrival checks, active maintenance rules, handover validation, and post-project audit.
Operational templates: vendor manifest, TCA (sheep-dip) scan form, jump-host checklist, backup & rollback verification, PTW signoff templates.
Safety-first enforcement: two-person integrity for safety changes, LOTO integration, no-touch lists for SIS/ESD unless explicitly in scope.
Standards mapping: aligned to accepted OT guidance and security standards so you can show auditors how controls meet recognized expectations.
Quick wins + roadmap: implement immediate controls in days and mature to advanced protections (PKI, immutable backups, continuous behavioral analytics).
If you’re responsible for OT availability, safety, procurement or compliance in energy, manufacturing, chemical, pharmaceutical or utilities, this checklist gives you the operational rigour you need without stopping production.
Key takeaways from the checklist
Require a tool manifest and TCA scan before any OT connection. No exceptions.
Replace standing vendor VPNs with jump-hosts and time-boxed accounts. Record every session.
Create a mandatory last-known-good backup and verify restore in a non-production testbed before making changes.
Enforce two-person verification for any safety-affecting changes to SIS/ESD logic.
Disable wireless and cameras at BIOS/UEFI level where possible; store personal devices outside OT zones.
Log and centralize all activity during maintenance windows and review immediately after work completes.
These steps reduce the most common root causes of vendor-related incidents with minimal operational overhead.
How Shieldworkz helps you operationalize the checklist
Shieldworkz turns the checklist into capability quickly and safely:
Discovery & Pilot (7-14 days): passive mapping of maintenance touchpoints and identification of high-risk assets used in vendor interventions.
PTW & Policy Integration: tailor the checklist to your existing Permit-to-Work, LOTO and safety governance; produce sign-off matrices and approval workflows.
Sheep-Dip & Tooling Implementation: design and operate a TCA inspection station, create offline AV update processes and seed a trusted tool whitelist.
Jump-Host & Session Recording: deploy bastion architecture with MFA, just-in-time credentials, session capture and audit pipelines.
Backup & Recovery Validation: implement immutable/air-gapped backups, test restore procedures, and document RTO/RPO metrics.
Training & Exercises: role-based training for vendors, escorts and engineers plus tabletop and live drills covering emergency rollback and insider scenarios.
Operational Monitoring: enhanced surveillance during maintenance windows-behavioral baselining tuned to maintenance activities to catch anomalies quickly.
Deliverables: PTW templates, TCA SOP, bastion configuration pack, backup/restore scripts, training materials, a site-specific 90-day roadmap, and a leadership dashboard showing KPIs (inventory coverage, vendor session recording rate, MTTD for maintenance anomalies).
Take action now
Download the OT Cybersecurity for On-Site Maintenance checklist to receive the complete five-phase playbook, templates and an implementation starter plan. Fill out the form to get the checklist and schedule a complimentary 30-minute scoping call with a Shieldworkz OT specialist - we’ll help you identify high-impact pilots and create a non-disruptive implementation plan.
Download your copy today!
Get our free OT Cybersecurity for On-Site Maintenance Checklist and make sure you’re covering every critical control in your industrial network
