Information strategy planning (ISP) pursues alignment of business strategy and IT (Information Technology) strategy as well as derivation of feasible and valuable IT projects. However, conventional ISP methodology hardly obtains the objectives because of its intrinsic shortcomings. Diverse ways are proposed for the improvement of the conventional methodology including, for example, combination of EA (Enterprise Architecture) with ISP. Meanwhile, six-sigma methodology which is characterized by quantification, scientific and systematic approach, customer orientation, process orientation has been gaining considerable attention and extending its application scope continuously. In this paper, an innovative ISP methodology is proposed by decomposing activities, methods, and tasks from conventional ISP process and reorganizing them into DMADOV six-sigma framework. In addition, the usefulness and applicability of the newly proposed methodology are provided using an electronics company example. The methodology enhance the possibility of producing future oriented and beneficial IT projects by associating IT strategy and the projects in the form of quantified causal relationship. Besides, it can also increase the objectivity of IT vision and strategy.