Answer:
Part a: The effective time is 10.5 hours.
Part b: The SCV of Effective Process times is 0.130.
Part c: The value of the Standard Deviation of the Effective process times is 3.80
Explanation:
Part a:
The effective time t_e is given as
Here t_p is the time taken to complete the paint job which is given as 10
A is the availability which is given as
here M_TBF is the mean time between failures which is given as 200 hours
M_R is the mean repair time which is given as 10 hours so
So the effective time is calculated as
So the effective time is 10.5 hours.
Part c:
The Standard Deviation of the Effective process times is given as
Here
σ_e is the standard deviation of the effective process time which is to be calculated
σ_p is the standard deviation of time taken to complete the paint job given as 2
A is the availability calculated above as 0.9524
M_R is the mean time of repair given as 10
σ_R is the standard deviation of time taken to repair given as 10
t_p is the time taken to complete a paint job which is given as 10
so the equation becomes
So the value of the Standard Deviation of the Effective process times is 3.80
Part b
The SCV of Effective Process times is given as
here both values of σ_e and t_e are calculated in above parts as 3.89 and 10.5 respectively so the equation becomes.
So the SCV of Effective Process times is 0.130