Update hero-implementation-details.md

documentation/general/program-scale-testing-requirements/hero-implementation-details.md

@@ -167,7 +167,7 @@ Latency is the time it takes for a packet to go through the device under test.
 
 Latency value is most accurate when we have highest PPS, smallest packet, and zero packet loss. and is measured using IxNetwork and Novus card.
 
-When testing the smart switch we have to run a test to get the switch latency without running the traffic through the DPU and then get the total system latency with the understanding that each packets travel once through the NPU to reach the DPU, than it travel through the DPU and once more it will travel through the NPU after it leave the DPU. 
+When testing the smart switch we have to run a test to get the switch latency without running the traffic through the DPU and then get the total system latency with the understanding that each packets travels once through the NPU to reach the DPU, than it travels through the DPU and once more it will travel through the NPU after it leave the DPU. 
 
 smart switch latency = 2 x NPU latency + DPU latency