The 3 Layers of Automation ROI
When justifying a $100k robot cell, most shops stop at Labor Savings. This is a mistake. The ROI comes from three distinct layers.
Layer 1: Labor Savings (The Obvious)
Formula: (Operator Hourly Rate × Hours Automated) - Robot Maint Costs
This is the base. If you replace 2000 hours of a $25/hr operator, you save $50k/year. But this rarely justifies the investment on its own (2-3 year payback).
Layer 2: Utilization Increase
Formula: (Extra Spindle Hours × Machine Hourly Rate)
A robot takes no breaks. It works through lunch (5 hrs/week gained). It starts instantly at 8:00 AM. This typically adds 10-15% more capacity to the existing shift.
Layer 3: Unattended Hours
Formula: (Ghost Shift Hours × (Machine Rate - Labor Rate))
This is the "Pure Profit" layer. Running 4 hours after everyone leaves yields pure revenue with almost zero marginal cost. This creates a 6-month payback.
Step-by-Step Calculation
Scenario: $100,000 Robot Cell. $80/hr Shop Rate.
- 1. Labor Savings (1 Operator, 1 Shift)+$40,000 / yr
- 2. Efficiency Gain (No breaks, +1 hr/day)+$20,000 / yr
- 3. Ghost Shift (Running 3 hrs/night)+$60,000 / yr
- Total Annual Return$120,000 / yr
Payback Period: $100k / $120k = 10 Months