(CNN) The year is 2020. A group of warehouse workers are locking up for the weekend.

As the lights go off, a swarm of buzzing drones fly into the darkness.

Over the coming days, they will zoom up and down the aisles, updating the inventory for when their human colleagues return on Monday morning.

This isn't a scene from a sci-fi film.

South African start-up Drone Scan is working on a device which they believe will revolutionize working lives worldwide.

More fun than climbing ladders

Despite its name, Drone Scan does not manufacture drones. Instead, it makes the clever device which can be attached to drones to scan barcodes.

The device uses lasers and details of the warehouse's dimensions to navigate the drone. By measuring its distance from the ground and walls, it calculates the drone's position.

Every time it scans a barcode, it automatically updates the central log with the exact location of that product.

The Drone Scan is attached to a DJI Matrice, which -- as opposed to more "easy on the eyes" consumer products -- is designed for commercial use and can be customized and controlled externally.

Jasper Pons, co-founder of Drone Scan, says this technology will save large companies millions of dollars every month by cutting man hours during stock-takes.

The drone can also fly up to the harder-to-reach higher shelves.

"We think the workers are going to love them," says Pons. "They are going to say: 'Give us the drones and give us back our weekends.'"

Fishing for gold

The idea for Drone Scan came after co-founder Jasper Pons started using a homemade drone to map fishing sites and film a canoe race on the Msunduzi river near Pietermaritzburg, in South Africa

"I thought, if this thing can lift a camera it can lift a barcode scanner up in a warehouse," says Pons.

Having worked with warehouse software in the past, the drone was a logical step towards speeding up data collection for Pons.

The company, which was founded in 2013, has since landed a pilot project in Europe.

Co-founder Craig Leppan cannot disclose the client's name, but says it is a large multinational company.

"They've indicated they have over 400 warehouses worldwide in need of this solution."

Could change warehouse design

"Continuous inventory is almost a dream within warehouse logistics," says Leppan. "Eventually you will have the drones working away in the warehouses at night when everybody is asleep."

The technology has potential to improve efficiency for large delivery giants such as Amazon. "The drone will help make their system more accurate which means less time spent looking for stuff when it's needed," says Pons.

While these drones may be the ideal workers -- they don't complain or need weekends off -- they do need their batteries recharging, a limitation to the technology the team is currently working on. They envisage a future where drones fly themselves to charging pods.

Another major drawback is that, currently, the drones require a person to control them with a joy-stick-like device.

The company hopes autonomous drones could be available in as little time as one year.

"[In the meantime], we envisage that even the manpower of flying the drone and someone recording the drone's scans on a tablet is faster than the conventional team of a forklift driver and a scanner," says Leppan.

"We've heard from people who are thinking about designing new warehouses which are drone friendly."

Let's hope the drones are friendly, too.