Abstract
It is necessary to consider both of the benefits and costs brought by a service in order to realize the high-value added service. However, the costs and benefits which customers in groups receive vary from customer to customer. This research aims to suggest a design method for high-value added service in consideration of the benefits and costs for each customer in groups. Especially, this paper proposes a method to represent the vector of the improvement of satisfaction and momentary costs for customers in a service. And this vector supports designer to make a decision about choosing improvement plans.
