Pulp and paper manufacturing is a cornerstone of the Pacific Northwest economy. Mills operate Distributed Control Systems that manage complex processes: pulping, bleaching, paper formation, drying, and finishing. These DCS installations are often 20-30 years old, running legacy hardware and software, but still performing reliably. Yet the threat landscape has changed dramatically. Upgrading DCS systems requires balancing operational continuity, cost, and security.
The challenge is not whether to modernize, but how to do so without disrupting a process that operates continuously and generates millions in revenue per day. A modernization strategy that ignores operational risk will fail in execution.
Assessing Legacy DCS for Modernization
Begin with an inventory of your DCS: which controllers, which sensors, what networks, what software versions, what's supported by vendors, what's obsolete? Segment your system into zones: critical process areas (core pulping, paper formation) modernize slowly; support systems (maintenance, energy monitoring) can modernize faster.
Evaluate the security posture of your current DCS. Is it air-gapped from corporate networks? Does it have external connectivity? Are there known vulnerabilities in the controllers or software? This assessment drives your modernization priority: high-security-risk areas should modernize first, low-risk areas can wait.
Modernization Strategies
- Segmented Replacement: Replace one section or line at a time, validating new systems operate correctly before moving to the next section. This reduces operational risk and allows staff to gain experience with new systems incrementally.
- Compatibility and Bridging: New DCS systems often need to integrate with legacy systems still running. Use bridging protocols (OPC UA gateways, protocol converters) to enable communication between old and new while maintaining security boundaries. This allows gradual transition rather than "rip and replace."
- Vendor Selection and Lock-in Avoidance: Modern DCS vendors offer better security than legacy systems, but they also introduce long-term dependency. Choose vendors with open standards (OPC UA, standard protocols) rather than proprietary systems. This reduces future lock-in and enables multi-vendor architectures.
- Cybersecurity by Design: New DCS should incorporate modern security: strong authentication, encryption, segmentation, logging. Avoid assumptions that "new systems are more secure." Insist on security features and proper configuration from day one.
Operational Continuity and Testing
Paper mills operate continuously with minimal downtime. Modernization windows are constrained to scheduled maintenance, typically a few weeks per year. Plan accordingly. Pilot new systems during off-peak or maintenance periods. Test extensively in parallel with legacy systems running. Maintain detailed runbooks and operator training before cutting over to new systems.
Post-cutover, expect issues. Have contingency plans to revert to legacy systems if new systems fail. Train staff on both old and new systems during transition periods. Monitor new systems intensively for weeks after deployment, looking for unexpected behaviors or performance issues.
Pacific Northwest pulp and paper mills are among the most sophisticated OT operations in the world. We understand the operational reality of modernizing DCS systems while maintaining production and security. Let's discuss your DCS modernization roadmap.
This article was written by the Cascadia OT Security practice, which advises Pacific Northwest data centers and manufacturers on industrial cybersecurity. For engagement inquiries, reach our practice team.