Key takeaways:
- Build resilience without downtime: Use passive asset discovery, strong network segmentation, and controlled remote access to strengthen cybersecurity without interrupting production or altering control systems.
- Secure legacy systems smartly: Protect older PLCs and SCADA equipment through network isolation, virtual patching, and vendor access controls instead of risky patching or code changes.
- Empower people as the first line of defense: Integrate short, role-based cybersecurity training — like shift-starter huddles and “stop and verify” practices — into daily routines to reinforce safe behavior without slowing operations.
Uptime is everything is food and beverage manufacturing. You know you need to harden your operational technology (OT), but how do you do so without interrupting schedules, compromising quality, or denting overall equipment effectiveness (OEE)?
Here’s a practical, low-friction approach tailored for plant leaders, with concrete steps for securing legacy equipment, running risk assessments during maintenance windows, and training frontline teams to be your strongest cyber‑defense.
Start with “no‑unplanned‑downtime” security
Good OT security should feel like good engineering: conservative, layered, and invisible to the line when it’s running. International partners led by the U.S. Cybersecurity and Infrastructure Security Agency (CISA) emphasize principles that put safety and business continuity first, including segmentation, restricted remote access, tested manual fallbacks, and change control that respects production rhythms.
Frame your approach around three non‑negotiables:
- Know what you have, passively. Build a living asset inventory of programmable logic controllers (PLCs), human-machine interfaces (HMIs), variable frequency drives, and supporting servers without touching the line. Use span/TAPs, switch telemetry, and log data, not agents. CISA’s 2025 OT Asset Inventory Guidance details how to do this and why it improves maintenance reliability and risk management.
- Segment like you mean it. Use the ISA/IEC 62443 “zones and conduits” model to separate production cells, quality labs, maintenance laptops, and corporate IT. This way, a problem in one area can’t race through your plant. (Think of it as hygienic piping for data.)
- Control remote access at the edge. Time‑bound accounts, multi‑factor authentication (MFA), jump hosts, and allow‑listed protocols via your firewall/VPN keep vendors and engineers effective and safe. Recent government guidance spotlights hardening network‑edge devices used for remote access.
Why this works for uptime: These actions occur outside the real‑time control loop. They don’t change ladder logic or touch setpoints, so they don’t stall production.
Securing legacy equipment without rewriting a line of code
Legacy PLCs and older supervisory control and data acquisition (SCADA) servers are everywhere in food manufacturing, and they often can’t be patched quickly. Focus on compensating controls that protect them in place:
- Ring‑fence old assets. Put legacy PLCs behind a cell firewall; allow only required ports from specific engineering workstations (a “default‑deny” rule set). Map this to your 62443 zones/conduits so it’s standardized across lines and sites.
- Broker remote support. Force all vendor access through a monitored jump server, and enforce MFA and one‑time windows. Current joint guidance stresses disciplined architecture records and third‑party risk controls.
- Use virtual patching. Where patching must wait, apply intrusion‑prevention/allow‑listing at the cell firewall or host to block known bad patterns while you schedule a proper update. Guidance on protecting network edge devices explains why this perimeter is a high‑value control point.
- Maintain manual modes. Test manual overrides and paper standard operating procedures (SOPs) so the line stays safe if a workstation is quarantined. The Principles of OT Cyber Security explicitly prioritize tested manual operation capabilities.
- Buy smart going forward. Fold security into procurement checklists — ask for 62443 certification, hardened defaults, and patch lifecycles. NSA and partners published guidance on secure OT product selection to help owners/operators.
Run risk assessments during maintenance windows
Goal: Get a defensible risk view without unplanned stoppages.
Pre‑window prep (deskwork only):
- Pull your current definitive view of the OT architecture: assets, data flows, dependencies. New CISA/UK NCSC guidance explains how this single, continuously refreshed record improves risk prioritization.
- Tie risks to the governance and “Identify/Protect/Detect/Respond/Recover” functions in NIST Cybersecurity Framework (CSF) 2.0, so findings translate cleanly to corporate reporting.
Window activities (time‑boxed, low‑impact):
- Passive capture first: sample network traffic at the cell level to confirm what talks to what.
- Targeted, vendor‑approved checks: run only non‑intrusive diagnostics on critical HMIs/servers; defer any scan that risks device lockups.
- Patch safely: apply pre‑tested patches/firmware on non‑redundant assets only if rollback images are ready; otherwise use virtual patching until the next outage.
Post‑window wrap‑up (no plant impact):
- Update your asset inventory and “definitive view” with deltas; log a change record; feed gaps into the next window.
Tip: Many OT incidents still start with unsophisticated methods (default passwords, exposed remote services). Closing these basics is high ROI and typically requires no line downtime.
Train the frontline like you train food safety
Most cyber risk in breaches still involves people — phishing, misuse of credentials, or rushed workarounds. Keep training bite‑sized and production‑aware:
- Shift‑starter micro‑huddles (5-7 minutes): One scenario a week: “A vendor requests remote access after hours — what’s our process?”
- “Stop and verify” culture: Make it as normal as checking allergen labels. Operators pause when a login prompt or USB stick appears and call the shift lead.
- Role‑based drills: Maintenance techs practice quarantining an HMI, and supervisors rehearse the call tree. Map drills to plain‑English versions of attacker behaviors documented in MITRE ATT&CK for ICS so exercises stay realistic without the jargon.
- Measure what matters: Track phishing‑report rates and response times during drills alongside OEE to prove security isn’t slowing the line.
Quick vendor checklist (use sparingly, standardize broadly)
- Does the solution support agentless OT discovery and create exportable architecture views? (Needed for your “definitive view.”)
- Can it enforce zone/conduit policies without rewriting PLC logic?
- How are edge devices (firewalls/VPNs) hardened and monitored over time?
- What’s the product’s security lifecycle (patch cadence, hardening guide, 62443 alignment)?
FAQ: OT cybersecurity that won’t slow your line
Q: Will these steps slow down operators or maintenance?
A: No. Done right, controls live at the network edge or in jump hosts, not inside the PLC scan cycle. Micro‑huddles replace long training days, and maintenance‑window work is time‑boxed. CISA’s principles explicitly balance safety and continuity.
Q: We have older PLCs and HMIs we can’t patch quickly. What’s the safest move?
A: Ring‑fence them with 62443 segmentation, restrict protocols, turn on MFA for any remote access, and use virtual patching until the next planned outage.
Q: How do we start an asset inventory without agents or downtime?
A: Use passive network monitoring, switch logs, and engineering workstation records to build your initial list; then maintain it continuously.
Q: What’s the minimum training frontline staff actually need?
A: Weekly 5-7 minute scenarios, a “stop and verify” SOP, and quarterly drills mapped to realistic adversary behaviors. Keep it practical, plant‑specific, and measurable.
Q: How often should we run risk assessments?
A: Use every scheduled maintenance window to update risks, apply pre‑tested patches, and refresh the architecture view.
Q: What threats matter most to manufacturing right now?
A: Ransomware remains active across industrial sectors and basic hygiene gaps are still exploited (default passwords, exposed remote services). Keep remote access tight and close the simple doors first.
You don’t need to choose between secure and on‑schedule. Start with passive visibility and segmentation, broker remote access, use maintenance windows for low‑risk improvements, and make security part of the daily routine on the floor.
Aligning to fresh, reputable guidance — NIST CSF 2.0 for governance and CISA’s 2025 OT asset‑inventory framework for execution — gives you momentum you can scale across sites without derailing production.
