A manager wants to assign tasks to workstations as efficiently as possible and achieve a desired daily output of $60$ units. The department operates $9$ hours per day. Assign the tasks shown in the following precedence network diagram $($The number are the task times in minutes$)$ to workstations using the following rules: most$-$following tasks first and in case of a tiebreaker select the task with the longest$-$operating$-$time. What is the efficiency?

A$)$ Fill in the table below with your final assignments, indicating the station ID in the blank cell according to your solution. Only enter the numerical value that corresponds to the station ID $($e$.$g$.1,2,3,$ etc.$)$ to which the task on the right side of the cell has been assigned.

A $(3$ min$)$

B $(3$ min$)$

C $(2$ min$)$

D $(4$ min$)$

E $(2$ min$)$

F $(5$ min$)$

G $(3$ min$)$

H $(3$ min$)$

I $(6$ min$)$

B$)$ What is the efficiency?

Efficiency $=$