Reliability

Question 1

MTBF

Answer 1

mean time between failures

Question 2

Define reliability:

Answer 2

The probability that the system will operate as expected for an expected period of time

Question 3

Define maintainability:

Answer 3

The probability of performing a successful repair within a given time.

Question 4

Formulae: Lambda

Answer 4

Failure Rate = 1/MTBF

Question 5

For a constant failure rate, the probability distribution of reliability is _____.

Answer 5

Exponentially decay

Question 6

Describe bathtub phases:

Answer 6

1. High risk of failure early on
2. Moderate failure during operations expected duration
3. high failure as wear out occurs

Question 7

We can increase fault tolerance by creating _______./

Answer 7

Redundancy

Question 8

Formulae: Reliability

Answer 8

R = e^(-Lt)
or
R = e^(-t/MTBF)

Question 9

Formulae: Series Reliability

Answer 9

R = R1R2….*Rn

Question 10

Formulae: Parallel Reliability

Answer 10

R = 1 - (1 - R1)(1 - R2)…*(1 - Rn)

Question 11

Designing redundancy in ______ increases ________.

Answer 11

parallel, reliability

Question 12

Name some ways to increase reliability:

Answer 12

1. Decrease time between failures
2. Provide ample design margins & contingencies
3. Add redundancy
4. Reallocate system performance & resources to adjust
5. Decrease Complexity