A customer wants delivery to be ensured between 10am and 2pm. Your truck leaves the factory at 4am and the time taken to reach the customer is normally distributed with an average of 8 hours and a standard deviation of 1 hour.
a. What is the process capability ratio of the process?
b. What is the probability that the current delivery process will be on delivered between 10am and 2pm (in other words, what is the service level)?
c. What specific action(s) (in terms of mean and standard deviation targets to be achieved) would you take to improve the ability of the delivery process to be a 6-sigma process?
d. If the mean delivery time was delayed until 12:30pm, but the standard deviation improved from 1 hour to 0.5 hours, what would the service level be for this new mean and standard deviation?