Great question! Dealing with Mitsubishi PLC components can be tricky when you're trying to figure out if something is truly obsolete or just temporarily unavailable. Here's how I approach it:

First, for distinguishing between genuine obsolescence and temporary disruptions:

1. Check official channels - Genuine obsolescence announcements come directly from Mitsubishi through formal EOL (End of Life) notices with specific timelines, usually 6-12 months notice. Temporary disruptions typically come from distributors as 'supply chain issues' without formal manufacturer announcements.

2. Look for patterns - If multiple components from the same product family are affected, it's more likely obsolescence. If it's isolated components across different families, probably supply chain.

3. Monitor lead times - Temporary disruptions usually have extended but finite lead times (3-6 months), while obsolescence means 'no longer manufactured' with limited remaining stock.

4. Check for alternatives - Manufacturers usually provide migration paths or compatible replacements for obsolete parts, which they don't do for temporary shortages.

For buffer stock strategy without tying up too much capital:

1. Tier your inventory - Classify components by criticality. Keep 3-6 months of buffer for mission-critical parts, 1-2 months for important ones, and rely on distributors for less critical items.

2. Use consignment inventory - Work with distributors who can hold buffer stock for you, only paying when you use it.

3. Implement a 'just-in-case' approach - Instead of blanket buffer stock, focus on components with long lead times or those showing obsolescence warning signs.

4. Leverage supplier partnerships - Some distributors offer obsolescence management programs where they monitor component lifecycles and provide early warnings.

5. Consider alternative sources - Sometimes third-party or refurbished components can serve as emergency backups without the capital commitment of new stock.

The key is balancing risk with capital efficiency - you want enough buffer to keep production running, but not so much that your money is sitting on shelves instead of working for your business.