Assuming the following:
L=Process Length of the oven t=Desired profile time in mins(depends on the paste/glue used) l=PCB length l1=gap between consecutive PCBs
Then the total no. of PCBs per hour is"
(L*60/t)/(l+l1)
Vinit
(http://www.smtnet.com/Forums/Index.cfm?CFApp=1&Message_ID=54218)