Test Cost

Test cost is the expense of electrically testing each device — including equipment, labor, facilities, and materials, typically $0.10-$2.00 per device, representing 5-20% of total manufacturing cost and a major target for cost reduction efforts.

What Is Test Cost?

• Definition: Total cost to test one device.
• Typical: $0.10-$2.00 per device depending on complexity.
• Components: Equipment, labor, facilities, consumables.
• Impact: 5-20% of total manufacturing cost.

Why Test Cost Matters

• Profitability: Significant portion of manufacturing cost.
• Competitiveness: Lower test cost improves margins or enables lower prices.
• Volume: High-volume products amplify test cost impact.
• Optimization: Major opportunity for cost reduction.

Cost Components

• Equipment: Tester depreciation and maintenance (40-60%).
• Labor: Test operators and engineers (20-30%).
• Facilities: Cleanroom space, utilities (10-20%).
• Consumables: Probe cards, sockets, handlers (5-10%).
• Yield Loss: Cost of overkill and escapes (5-15%).

Calculation

def calculate_test_cost(tester_cost_per_hour, test_time_seconds, 
                        labor_rate, overhead_rate):
    # Equipment cost
    equipment_cost = (tester_cost_per_hour / 3600) * test_time_seconds
    
    # Labor cost (per device)
    labor_cost = (labor_rate / 3600) * test_time_seconds
    
    # Overhead
    overhead = (equipment_cost + labor_cost) * overhead_rate
    
    total_cost = equipment_cost + labor_cost + overhead
    return total_cost

# Example
cost = calculate_test_cost(
    tester_cost_per_hour=500,
    test_time_seconds=5,
    labor_rate=50,
    overhead_rate=0.3
)
print(f"Test cost: ${cost:.3f} per device")

Reduction Strategies

• Reduce Test Time: Optimize patterns and parallel testing.
• Increase Utilization: Maximize tester uptime.
• Adaptive Testing: Skip unnecessary tests.
• Automation: Reduce labor content.
• Yield Improvement: Reduce retest and rework.

Trade-offs: Lower test cost must be balanced against quality (coverage) and yield (overkill vs escapes).

Test cost is a major profit lever — optimizing it while maintaining quality is critical for competitive manufacturing economics.