My first advice would be to do this :
you grab a slicer software (say Cura)
you put the following data : printing speed 50mm/s, travel speed 80mm/s ; shells : 2 ; infill 25%; lower and upper full surfaces : 2
if you are curious about a printer you enter his printing volume, otherwise you just go with 25cm cubed
you see how many of your items you can squeeze in the print bed
this will give you the print time for the items on the bed
you see if in 24 hours you can do enough prints to reach 60 items.

If you can't, that will just be a reminder that 3D printing is not a process designed for mass production.

If you can, I would make sure you add enough downtime to ensure that you have a certain degree of margin and at least 1 or 2 more runs a day : shit happens.

Don't believe any builder that tells you you can print faster than 60mm/s on a FDM 3D printer : yes you can but the quality is so awful it's not worth mentioning.