The 3 Stages of Maintenance
Most machine shops are stuck in Stage 1 or 2. Stage 3 is where the profit margins live.
- 1. Reactive (Run-to-Failure): "Fix it when it smokes." Highest cost due to unplanned downtime and collateral damage.
- 2. Preventive (Interval-Based): "Replace it every year." Wastes money by replacing good parts too early.
- 3. Predictive (Condition-Based): "Replace it when it vibrates." Optimizes part life and eliminates surprises.
The P-F Curve Explained
The P-F Curve illustrates the interval between Potential Failure (P) and Functional Failure (F).
Failure Detection Timeline
By the time you can hear a spindle bearing screaming, you are already at the end of the curve. The damage is done. Predictive tools (Vibration, Oil Analysis, Thermography) detect the issue months in advance (Point P), giving you time to order parts and schedule the repair.
Calculating the ROI
A simple vibration monitoring system might cost $2,000 per machine. Is it worth it?
The $40,000 Saving Scenario
Without Monitoring:
Spindle siezes mid-cut on a Friday. Customer rush order is late.
Rush Repair: $15,000
Overtime: $2,000
Lost Production (3 days): $12,000
Late Penalties: $5,000
Total: $34,000
With Monitoring:
Sensor alerts "High Vibration". Trends show 2 weeks remaining.
Scheduled Rebuild: $8,000 (Standard Exchange)
Downtime: Scheduled (0 impact)
Total: $8,000
ROI = 325% on first failure prevention.