Determine the availability for each of these cases:

a. MTBF = 40 days, average repair time = 3 days

b. MTBF = 300 hours, average repair time = 6 hours

20. A machine can operate for an average of 10 weeks before it needs to be overhauled, a process

which takes two days. The machine is operated five days a week. Compute the availability of this

machine. (Hint: All times must be in the same units.)


. A manager must decide between two machines. 

The manager will take into account each

machine’s operating costs and initial costs, and its breakdown and repair times. Machine A has a

projected average operating time of 142 hours and a projected average repair time of 7 hours. Projected times for machine B are an average operating time of 65 hours and a repair time of 2 hours.

What are the projected availabilities of each machine?