This is a classic supply chain challenge that many manufacturers face! With 6-month lead times for critical Mitsubishi automation components, you need a smart hybrid approach that blends just-in-time efficiency with just-in-case security. Here's what I'd recommend:

First, categorize your components using ABC analysis. Group A items are your critical Mitsubishi parts with long lead times - these need special treatment. For these, maintain strategic safety stock based on your maximum usage during peak demand periods plus the 6-month lead time buffer. Calculate this using the formula: (Maximum Daily Usage × Maximum Lead Time) - (Average Daily Usage × Average Lead Time).

Second, implement a tiered approach: use JIT for common, readily available components while maintaining buffer stock for those long-lead-time Mitsubishi parts. Consider keeping 10-15% buffer stock for your top-selling critical components.

Third, explore alternative suppliers for critical components where possible, or work with Mitsubishi to get better visibility into their production schedules. Some companies use predictive analytics to forecast when they'll need to reorder those 6-month lead time items.

Finally, invest in inventory management software that gives you real-time visibility and automated reorder triggers. This way, you can maintain JIT efficiency for most items while protecting against stockouts for those critical Mitsubishi components that take forever to replace.

The key is finding that sweet spot where you're not tying up too much capital in inventory, but you're also not risking production shutdowns waiting for parts!