How long does a memorial service usually take?

I just attended a memorial service for a colleague. It usually lasts about one and a half hours. It depends on the region. I am in Shanghai.

I started signing autographs and getting flowers, then my family members went in, and then my friends...it lasted about an hour and a half if the family members were fine.

There will be cremation after the ceremony. There is no need to go to the cremation. Family members and relatives can go. Friends who want to go can also go together.