Hey there! As someone who's been through the lights-out manufacturing journey, I can tell you there are some eye-opening realities that don't get discussed enough. First off, that 'lights-out' name is misleading - you'll actually need MORE lighting for all those maintenance cameras and inspection systems! Here's what veteran engineers wish they knew:

1. The 'hidden' maintenance army: You're eliminating floor workers, but you're creating a whole new team of specialized technicians, programmers, and remote monitoring staff. These experts cost significantly more than traditional operators.

2. Infrastructure costs will shock you: Your electrical, network, and cooling systems need to be bulletproof. One power flicker that a human could recover from in minutes can mean hours of downtime as systems reboot and recalibrate.

3. The 'lights-sparse' reality: Most successful implementations aren't truly lights-out. They're 'lights-sparse' - you still need humans for changeovers, quality checks, and unexpected situations. Going fully unmanned is often more trouble than it's worth.

4. Software becomes your biggest bottleneck: Machines can run 24/7, but your software systems need constant updates, patches, and integration work. The IT costs are ongoing and substantial.

5. Supply chain vulnerability: When you're running 24/7, any material shortage or quality issue in your raw materials becomes catastrophic immediately. Your buffer stock needs are much higher than anticipated.

6. The knowledge gap: Veteran engineers often underestimate how much tribal knowledge gets lost. That operator who could 'feel' when a machine was about to fail? That intuition is gone, and you need expensive sensors and AI to replace it.

7. Implementation failure rates: Research shows 40-50% of lights-out initiatives get derailed by unexpected challenges. The transition is rarely smooth, and the learning curve is steep.

The smart approach? Start with one cell or line, not the whole factory. Build your expertise gradually, and always maintain some human oversight. The savings are real, but the path there is much rockier than the glossy brochures suggest!