Fingerprint recognition technology is making it a lot easier for companies to keep track of their employees.

Rosedale Hotel has adopted a fingerprint recognition system to check staff attendance.

All of its staff members have registered their fingerprints in the system.

When the employees put their registered fingerprint on a 1.5cm x 1.5cm sensor area after entering their identification number, the device records the login time in one or two seconds.

Compared with the traditional paper-card system, the fingerprint recognition system is more convenient.

According to Stephanie Cheung, assistant human resources manager at Rosedale Hotel, under the traditional paper-card system, each staff member generated at least 12 cards a year.

“It was extremely troublesome to keep so many cards in our database.”

Looking for an employee’s attendance records was a tiresome job under the traditional system.

“We had to search through thousands of cards in order to get a particular one,” Miss Cheung said.

Therefore, she appreciates the convenience of the new system.

“Now, with the new device, we simply click the name on a computer and then everything is there,” she said. “That saves us a lot of time and manpower.”

According to Li Him, an engineer at Hetrix computer company, a fingerprint recognition system works by locating the relative positions of minutiae, the unique points of a fingerprint.

The system chooses 12 minutiae to describe a fingerprint of a person since the relative positions of minutiae are different for every individual.

Said Mr. Li: “The computer memorises information from the minutiae’s relative postions for identification.”

Despite using only 12 points, it is not easy for a person to reconstruct or imitate another person’s fingerprints.

A fingerprint recognition system mainly works in two ways — by verification or identification.

In verification, users are required to enter a user identification number or to swipe a smartcard before scanning their fingerprint.

A sensor then compares the fingerprint with the relative positions of minutiae in the system’s records.

As for identification, users only need to scan their fingerprints.

The system then performs an auto-match for all the records in the system.

Normally, thumbs are used to recognise a fingerprint in the system.

However, the advanced system does not always work well for everyone.

Some people’s fingerprints are too vague to be recognized by the device.

This is partly because jobs like washing dishes may make fingerprints unreadable by the sensor.

Miss Cheung said that sometimes dishwashers check in the office without any problem in the morning, but authorizations are rejected when they check out after work.

In such a situation, they have to check out by using passwords instead of fingerprints.

Moreover, Keith Lau, vice president of sales and marketing at Hetrix, admitted that there is a chance of false rejection or false acceptance.

The system might falsely reject one person out of 100,000 and falsely accept one person out of 1,000,000.

However, the fingerprint recognition system is user friendly and cost effective.

Mr. Lau stressed that it is especially useful for companies with frequent personnel changes.

“For companies that have offices in different places, the system is especially useful,” he said.

Though the technology is not yet widely used in Hong Kong, Mr. Lau foresees that it will become more common in the future.