Karen Perez runs an office supply store that also performs simple office services, such as copying. It is time to purchase a new high-speed copier and Karen has learned that machine uptime is a critical factor in selection. She has gathered the following information on reliability and maintainability for the three copiers she is considering.

Given that all other factors are equal, which machine should she purchase?

Copier Mean-time Between Failures Mean time to repair

(Hours) (Hours)

Able Copy 40 1

Business Mate 80 4

Copy Whiz 240 8

Machine Able Copy

Explanation:

The computation is shown below:

Utilization rate = (Mean-time Between Failures) : (Mean-time Between Failures + Mean time to repair)

For Able copy, it would be

= (40 hours) : (40 hours + 1 hours)

= (40 hours) : (41 hours)

= 97.56%

For Business mate, it would be

= (80 hours) : (80 hours + 4 hours)

= (80 hours) : (84 hours)

= 95.24%

For copy whiz, it would be

= (240 hours) : (240 hours + 8 hours)

= (240 hours) : (248 hours)

= 96.77%

As we see the highest utilization rate is of Machine able copy. Therefore, this machine should be purchased.