Dawson's "Last Stop BBQ$"$ restaurant recently opened a drive$-$thru. Steven, the manager, is concerned that their processes are not efficient enough to satisfy the lunch$-$hour rush. Based on the information in the table, please answer the following questions. Assume operations are for only $1$ hour unless otherwise stated.

STEP TIME

$($seconds$)$ IMMEDIATE

PREDECESSORS

A$.$ Take order. $25$

B$.$ Collect money at window. $45$ A

C$.$ Gather drinks. $50$ A

D$.$ Gather food. $80$ A

E$.$ Put drinks and food in a bag. $28$ C$,$ D

F$.$ Give the order to the customer. $20$ B$,$ E

Assuming no more than $1$ worker per step, what is the maximum capacity of this process in units$/$hour$?$