Deck 20: Extension 4: Reliability

Question 1

Waygate's residential internet modem works well but is sensitive to power-line fluctuations.On average, this product hangs up and needs resetting every 200 hours.On average about 45 minutes is needed to reset this product.What is this product's availability?

A)Not in excess of .75
B)In excess of .75 but not in excess of .8
C)In excess of .8 but not in excess of .9
D)In excess of .9 but not in excess of .95
E)In excess of .95

Answer 1

E

Question 2

A system consists of two components, each of which must activate if the system is to activate.One component has a reliability of .99.The other has a reliability of .95.The components are independent of one another with respect to reliability.What is the overall system reliability?

A).99
B).95
C).94
D).90
E)Cannot be determined with this information.

Answer 2

C

Question 3

A system consists of two components, each of which must activate if the system is to activate.One component has a reliability of .99.The other has a reliability of .95.What is the overall system reliability?

A).99
B).95
C).94
D).90
E)Cannot be determined with this information.

Answer 3

E

Question 4

Redundancy is often more cost-effective than increasing individual component reliability.

Question 5

An electrical appliance will not work unless component QK does.Component QK's reliability is 0.95.Every other part of the appliance is 100% reliable.What would the reliability of the appliance be if a backup QK were added?

A).95
B).9975
C).9025
D).9205
E).9795

Question 6

Reliability is the probability that a product or system will function when activated.

Question 7

Product reliability involves both short-term and long-term perspectives.

Question 8

If a system depends on two sub-systems functioning when activated, the reliability of that system is equal to the lower reliability of the two sub-systems.

Question 9

The time between failures for an electrical appliance is exponentially distributed with a mean of 25 months.What is the probability that the next failure won't occur before 30 months have elapsed?

A)Not in excess of .2
B)In excess of .2 but not in excess of .3
C)In excess of .3 but not in excess of .4
D)In excess of .4 but not in excess of .6
E)In excess of .6

Question 10

Availability cannot be increased without improving the time between breakdowns.