This achievement will require you to beat the time of 15.1 seconds in the Ship Cargo training area during F.N.G..
This achievement will likely take a little bit of trial and error, but isn't too bad if you follow some tips. I recommend using the MP5 and taking a few runs to memorize the course first. It is important to know exactly what is around every corner for speed and accuracy; as you can get an accuracy bonus of up to 3 seconds off your time.
As for the strategy, repel, jump to the right and aim for the first two enemies. Sprint inside and grab the last enemy, sprint down the stairs killing the enemy at the bottom and load your flashbang. Turn the corner and throw the flash, preparing yourself by aiming down sights. Once it explodes, clear the enemies, sprint to the next room, and then hip fire the two enemies, loading your flash immediately after. Flash the last room, and walk backwards towards the exit as it explodes. Shoot the final two enemies through the small door gap and through the wall from outside, sprinting to the exit as possible. If done in under 18.1 seconds with a perfect accuracy bonus, the achievement will unlock.
You will also unlock: