Abstract
In these days, under a shortened term for developing series of new products, a corporation rather takes an attention to develop a product with a new value. However, even if the product is planed with an excellent concept, the product does not generate any significance as long as the concept is not reflected to the product. Additionally, there is a possibility that the shortened term for developing the product disregards the original concept. To solve such a problem, in this paper, the authors propose a method for understanding inconsistency in conducting a mission during a planning stage. By dividing a product concept into two parts (a plus part which contributes success in conducting a mission and a minus part which obstacles the success), causes and results relation between the plus part and the minus part in project phases is regarded as internal and external constraints.
