Legacy System Integration

Legacy System Integration refers to the process of integrating older IT systems—which are still operational but technologically outdated—with modern digital platforms, cloud services, or security frameworks. This is critical in the automotive sector where new ADAS（Advanced Driver Assistance Systems）must communicate with legacy ECU（Electronic Control Units）without compromising overall vehicle security. According to ISO/SAE 21434 and NIST SP 800-160, legacy systems often lack modern encryption and authentication capabilities, making them primary targets for cyberattacks. Unlike system modernization, which involves replacing old systems, legacy integration focuses on creating secure interfaces to maintain business continuity while mitigating risks. This requires a deep understanding of both legacy protocols and modern security standards to ensure data integrity and system availability across the entire automotive lifecycle.

Practical application follows a three-step methodology: Assessment, Design, and Validation. First, the enterprise conducts a comprehensive asset inventory and threat-risk assessment (TARA) as per ISO/SAE 21434 to identify legacy vulnerabilities. Second, a secure integration layer is designed, often utilizing Zero Trust principles, API gateways, or data-diode technologies to prevent lateral movement of threats. Third, continuous monitoring and compensating controls are implemented to manage risks that cannot be patched. For example, a Taiwanese automotive Tier-1 supplier integrated its legacy manufacturing control system with a new cloud-based ERP by implementing network segmentation and MFA（Multi-Factor Authentication）at the gateway. This initiative reduced unauthorized access attempts by 65% and ensured compliance with TISAX standards within six months.

Taiwanese enterprises typically face three challenges: technical debt, vendor dependency, and regulatory pressure. Many SMEs operate on legacy systems that lack documentation or vendor support, making integration both difficult and expensive. To overcome this, enterprises should adopt a phased approach: start with a risk-based inventory, prioritize legacy systems by criticality, and implement compensating controls like micro-segmentation. The second challenge is the lack of skilled personnel capable of managing both legacy protocols and modern security standards; investing in upskilling or partnering with specialized consultants is essential. Finally, as Taiwan's Personal Data Protection Act and international standards like ISO/SAE 21434 become more stringent, companies must ensure legacy systems do not leak sensitive data. A 90-day roadmap starting with a pilot integration project is recommended to demonstrate ROI before full-scale deployment.

Winners Consulting Services Co., Ltd. specializes in Legacy System Integration for Taiwan enterprises, delivering compliant management systems within 90 days. Free consultation: https://winners.com.tw/contact