Hey there! I completely understand your dilemma as a purchasing director facing the Siemens S7-400 discontinuation. This is a classic challenge in industrial automation, and you're right to be thinking strategically about it. Here's what I've found: Siemens has officially announced the S7-400 phase-out, with the PM400 milestone (product discontinuation announcement) happening on October 1, 2025. The good news is that Siemens typically provides a 10-year spare parts guarantee from this announcement date, so you have some breathing room. For your strategy, I'd recommend a balanced approach: 1. Immediate Action: Identify your most critical S7-400 modules and consider strategic stockpiling for the next 2-3 years. Focus on components that are mission-critical and have long lead times. 2. Migration Planning: Simultaneously, start planning your migration to newer platforms like the S7-1500 series. Siemens provides comprehensive migration guides and tools, but this is a significant project that requires careful planning. 3. Risk Assessment: Consider the cost of unplanned downtime versus the investment in migration. While migration has upfront costs, the long-term benefits include improved performance, better diagnostics, and future-proofing your operations. The smartest approach is to use the 10-year spare parts window to gradually transition while maintaining operational continuity. Start with a pilot migration project to understand the effort involved, then create a phased transition plan that aligns with your maintenance schedules and production cycles. What's your current timeline for addressing this challenge, and how many S7-400 systems are you managing?