To ensure continuous excavator operation with no idle time, the required number of dump trucks must be calculated using: Rule of thumb Number of Trucks = Truck Cycle Time ÷ Excavator Loading Time Example: Truck cycle time = 8 minutes Excavator loading time = 2 minutes → 8 ÷ 2 = 4 trucks (theoretical) However, real-world operations involve delays: -Dumping queue -Road conditions -Minor inefficiencies That's why we always add a buffer truck to avoid excavator downtime. So in this case: 5 trucks would be required in practice. Proper fleet balance ensures higher productivity and reduces fuel waste and idle time.