You know what keeps me up at night in a lights-out factory? It's not the robots or the fancy AI - it's the digital infrastructure and control software that orchestrates everything. Think about it: one failed sensor, a jammed feeder, or a network glitch can bring the whole automated line to a screeching halt when there's no human around to troubleshoot.

The real anxiety comes from the fact that in a fully automated setup, the control system becomes the brain of the operation. If that goes down, everything stops. No one's there to flip a switch or make a judgment call.

For budget-friendly redundancy, here's what I'd do:

1. Start with power redundancy - use UPS systems and battery control modules. They're relatively inexpensive compared to production downtime.

2. Implement ring network redundancy for your industrial Ethernet. This creates a closed loop so if one link fails, data automatically reroutes through the other path.

3. Instead of full redundant PLCs for every system, add basic hardwired controls in parallel for critical functions like level monitoring or emergency stops.

4. Use automatic power transfer switches for single-corded devices - they're affordable and provide instant fallback power.

5. Focus redundancy on the most critical sensors and control points first. You don't need to duplicate everything - just the components that would cause catastrophic failure.

The key is thinking in layers: start with the most vulnerable points and build redundancy outward as your budget allows. Even basic redundancy measures can prevent hours of downtime in a lights-out environment.