Q. Presume a program will experience a total of 200 failures. Preliminary failure intensity is 16 failure/ CPU hr. It has currently experienced 50 failures. Determine the following subsequent to specifying the formula

a. Current failure intensity

b. Decrement of failure intensity

c. Failure intensity at 100 CPU hr.

Ans:

i. Current failure intensity

λ (μ) = λ ₀ [1 - μ / v₀] = 16 [ 1- 50 / 200] = 12 failure / CPU hr

ii. Decrement of failure intensity

d λ / dμ = - λ ₀ / v0 = 16 / 200 = -0.08 CPU hr

iii. Failure intensity at 100 CPU hr

λ (_) = λ ₀ exp(-λ ₀ λ / v₀)

= 16 exp ( -16 * 100 / 200) = 16 exp(-8)