Consider a shirt$-$stitching process. The raw material for one shirt arrives as two sheets. One sheet $($the front$)$ goes to worker A who takes $5$ minutes to process it$.$ The other sheet $($the back$)$ goes to worker B who takes $10$ minutes to process it$.$ So A and B are done simultaneously, not sequentially. Once both front and back are ready, they go to worker $C$ who stitches them together $(4$ minutes$),$ then to D $($Ironing$,12$ minutes$)$ and to E $($packing$,5$ minutes$).$ All steps $($A$,$ B$,$ C$,$ D$,$ and E$)$ are necessary to create each finished unit. Each step employs a single worker. The utilization of this process is: