Ground handling at Singapore Changi International Airport

There is no detailed introduction to the ground handling work at Singapore Changi International Airport

I only know that there are three types of ground handling at Singapore Changi International Airport:

1) Singapore Airport Management Office (SATS)

2) Changi International Airport Management Office (CIAS)

3)

Swissport

It has been operating at Changi Airport since March 2, 2005. The Civil Aviation Authority of Singapore issued a 10-year ground handling license to it in order to cultivate a more competitive market. Swissport provides passenger services (such as passenger registration), ramp services (such as baggage handling) and cargo handling services. Currently in Changi, Swiss International Air Lines is its only customer.