The development of mobile communication technology is transforming the market of mobile communication devices, which is used to be merely for simple communication, into the one which offers features of personal digital assistant (PDA), fax communica- tion and Internet access. Unlike a mobile phone which comes out as a complete package and whose functions cannot be changed, a smart phone can be upgraded by its user, adding or removing apps as he pleases. OS’s of smart phones are iOS-based Apple, Google Android, Window Mobile, and others. Due to its convenience and powerful features, many people use smart phones its high price. On the other hand, consumer complaints are rising on poor A/S for occasional malfunction. This study analyzes how A/S cases can be classified into groups according to quality factors. We evaluate factors such as consumer impression and consumer satisfaction. By dual quality evaluation using KANO method, we would like to show the different A/S strategy for smart phones, compared with mobile phones.