Question

Consider a single machine workstation to which jobs arrive according to a Poisson distribution with a mean arrival rate of 12 jobs/hour. The process time of the workstation is exponentially distributed with a mean of 4 minutes. The expected number of jobs at the workstation at any given point of time is ___________ (round off to the nearest integer).

Show Answer

Answer :

Correct answer is : 4

arrived rate follows Poisson distribution,

λ = 12 Jobs / hours

Service rate follows exponential distribution,

t = 4 minutes

t = 4 60 h o u r s = 1 15 h o u r s , μ = 1 t = 15 J o b s / h o u r s

Now,

Expected number of Jobs i.e. length of system.

L s = λ μ λ

L s = 12 15 12

L s = 12 3

∴ Ls = 4 Jobs

Report
More Similar Tests

Related Tests