An integrated electronic-chip manufacturer has a demand for a specific component of 800 parts per 8-hour day. The manufacturer wants to design a lean system using containers. The containers the manufacturer used for this component held 20 parts. It takes about 4 hours to round-trip a container from one work center to the next and back again. The manufacturer also wants to hold 10% of safety stock of this part in its system.

How many containers should the lean system be using?

a. 5

b. 10

c. 20

d. 22

e. 30