A customer wants delivery to be ensured between 10 am and 2 pm. Your truck leaves the factory at 4 am and time taken to reach the customer is normally distributed with an average of 8 hrs and a standard deviation of 1 hr.
What is the process capability ratio of the process?
If you want to improve the ability of the delivery process to a 6-sigma process, what would be the new mean and standard deviation of the delivery time you should target? Can you recommend one practical action to achieve the target?