Hey there! That's a really tough situation you're facing - going from 2 weeks to 6 months lead time overnight is every purchasing director's nightmare. Here's how I'd approach building resilience in this scenario:

First, I'd immediately categorize those PowerFlex 525 drives as "critical single points of failure" since they control essential motors and processes. For these mission-critical components, I'd implement a multi-layered strategy:

1. Emergency buffer stock - Order at least 3-6 months' worth of inventory immediately, even if it means paying premium prices. This buys you time to implement longer-term solutions.

2. Supplier diversification - Start identifying alternative suppliers or distributors who might have inventory. Check authorized resellers, gray market options, and even consider refurbished units as temporary backups.

3. Cross-training and standardization - If possible, look at whether other drive families in your facility could be standardized to reduce dependency on this specific model.

4. Proactive maintenance - Work with maintenance teams to ensure existing drives are well-maintained to extend their lifespan while you secure replacements.

For the long term, I'd recommend implementing a spare parts criticality assessment tool that factors in lead time variability, failure patterns, and supply chain risks. This helps you prioritize which parts need larger safety stocks versus which can be managed more leanly.

The key is balancing immediate firefighting with building a more resilient system that can withstand future disruptions. It's painful in the short term, but essential for operational stability.