Why Downtime Risk Will Increase in 2026
Unstable supply chains, aging automation assets, and tightening maintenance budgets mean one thing: spare parts shortages will be more painful than before.
Even with predictive maintenance and scheduled shutdowns, unplanned PLC failure remains the most expensive risk in a factory.
A single failed ControlLogix CPU, CompactLogix power supply, or Ethernet/IP communication card is enough to freeze an entire production line.
2026 is not only about knowing what may fail — but having the right part in stock before it does.
To support procurement planning, we compiled the most failure-sensitive Allen-Bradley modules to watch carefully next year, with stocking recommendations for each.
The 12 Highest-Risk Allen-Bradley Failure Points
1. ControlLogix CPU Modules (1756-L71 / L72 / L73 / L81E Series)
Most common downtime trigger. Failure = full system loss.
Stocking advice: Keep at least 1 primary spare + 1 cold backup.
2. CompactLogix CPU 1769-L Series
Often used in cost-sensitive lines. Not always repairable.
Stock level: 1 spare per machine cell.
3. Ethernet/IP Communication Modules (1756-EN2T / EN3TR)
Network instability → production stops instantly.
Stock: 2 units minimum, especially for 24/7 lines.
4. Redundant Power Supplies (1606 / 1756-PA series)
PSU failure happens silently → sudden shutdown.
Stock: Replace in pairs, keep 2 spares.
5. I/O Analog Input/Output (1756-IA16 / OF8 / IF16)
Temperature drift & electrical noise increase fault rate.
Stock: High-usage plants require 2–4 spares per rack.
6. Digital I/O Cards (IP20/IP67 Types)
Field-device shorts + surge damage = common failure.
Stock: Monitor harsh-environment installations.
7. Servo Drive Interface Cards (Kinetix Series)
Motor control + motion sync — sensitive and expensive to stop.
Stock: Always hold one backup interface card.
8. Safety Relay / GuardLogix I/O
Failure → system locks out & cannot bypass.
Stock: 1–2 per line mandatory.
9. HMI Panels (PanelView Plus Series)
Touchscreen, backlight, interface wear-out.
Stock: 10–20% spare ratio recommended.
10. Industrial Switches (Managed/Unmanaged)
Switch death = plant death. Network = bloodstream of OT.
Stock: Dual spares in every control room.
11. Communication Cables & Breakout Harnesses
Cheap but most often overlooked.
Stock: Bundle-based stocking is most efficient.
12. Firmware-Locked Modules
If the firmware is unrecoverable → replacement becomes mandatory.
Stock: Always back up matching firmware units.
Recommended Spare Parts Stocking Strategy
| Category | Risk | Emergency Spare Level |
|---|---|---|
| CPU / EN2T / Communications | ⚠ Very High | ≥2 spares |
| Power & I/O | Medium-High | 1–3 spares |
| HMI & Drives | Medium | Preventive rotation |
| Cables / Sensors | Low but frequent | Bulk box reserve |
For real-time availability, you may check current stock here:
👉 Allen-Bradley Spare Parts — topautodevice.com/collections/allen-bradley
If you need mixed brand sourcing, browse also:
👉 Shop by Brands — Siemens, Omron, ABB, Honeywell, Schneider, more
How to Reduce Downtime by 70% Using Proactive Stocking
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Identify line-critical PLC modules
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Keep 1–2 emergency CPU & comm modules onsite
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Use multi-warehouse suppliers for 3-day delivery backup
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Prioritise firmware-locked components for early stocking
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Switch to replacement-instead-of-repair policies to shorten MTTR
To help plants operate without interruption, TopAutoDevice provides same-day dispatch + 3-day worldwide delivery supported by warehouses in the U.S., Shenzhen China, and Jiangsu China.
For MRO planning and BOM review, you can also send us your spare list anytime.
