Table 2. Variables in systems A and B

Variable	System “A”	System “B”
Total life cycle	20 years	5 years
Annual operating hours	6,000	6,000
Failure rate(λ) per 1 million hour	2,000	2,000
Time to repair	3 h	3 h
Time to replace	2 h	2 h
Cost of repair	$ 300	$ 300
Cost of replacement	$ 200	$ 200