The focus of Six Sigma is on meeting the requirements of customers. Even a small number of defects or complaints can mean the death of a product or service. If the airlines set a 99% success goal so that only one out of a hundred fell out of the sky before reaching its destination the customer would not be happy at all. If you processed 250,000 credit card bills monthly and operated at 4 sigma there would be 1,550 angry customers with inaccurate credit card bills. For the future of your services, here is the problem:
In short, setting high goals may be a matter of survival for your business.