A Tier-1 Automotive Supplier Replaces 20-Year-Old PLCs Mid-Production: What the Retrofit Timeline Looks Like

A mid-sized Tier-1 supplier in Ohio manufactures door panels and structural components for three OEMs. The facility runs two stamping lines, one progressive die assembly line, and a robot-attended welding cell. The control architecture was a patchwork: ABB AC890 drives on the main stampers, Siemens S7-300 PLCs managing sequence and interlocks, and point-to-point hardwired relay logic holding together the material handling. The system was stable. It was also obsolete. Spare parts lead times had stretched to 16 weeks. A single processor fault on the stamping line meant 8 to 12 hours of troubleshooting because no one under 50 on staff had worked with that CPU generation.