Great question! Based on my research, vibration monitoring is actually the most compelling 'low-hanging fruit' for getting quick ROI with IIoT predictive maintenance. Here's why:
Vibration sensors are relatively inexpensive, easy to install (often wireless), and they catch mechanical issues early - things like bearing wear, misalignment, or imbalance that would otherwise lead to catastrophic failures. The U.S. Department of Energy found predictive maintenance can yield ROI of about 10x the investment, and vibration monitoring is a key part of that.
Here's a solid pitch to management: Start with critical rotating equipment like pumps, motors, or fans that have high repair costs or cause production downtime. A pilot program on just 3-5 key machines can show ROI in 3-6 months by preventing just one major failure. Track the 'saves' - document avoided downtime hours, emergency repair costs, and reduced parts replacement.
Temperature monitoring is also valuable (especially for electrical equipment), but vibration gives you earlier warning for mechanical issues. Many modern sensors actually combine both vibration and temperature monitoring in one device, giving you the best of both worlds.
The key is to start small, prove the concept, then scale. Focus on equipment where unplanned downtime costs you the most - that's where you'll see the fastest return.