With increasingly fierce competition in food service industries, managers in restaurants are not only trying to attract customers via innovation of products or business models, but also offer services they had never done before. Restaurants are looking forward to make profit and offer different experience as well. Restaurants, however, not always offer services customers want. On the contrary, it is excessive. Excessive services results in customs' dissatisfaction of consume experience. This article, therefore, is trying to explode the ways to improve excessive services of restaurants based on the six-sigma and cause-effect diagram. Some suggestions are also provided for correlative service industries in the future as well.