Decision making paradigm has changed.Many managers in many companies have used decision support system(DSS) to optimize their decision making.Modified DSS bu using web infrastructure has helped managers make decision more effective and accurate.Web based DSS is not used by managers only,but personal aim too.In this paper,authors tried to explain the tahanifuzzy model methodology that used in developing model of DSS,in handphone purchasing case.The customer purchasing behavior/style and handphone features combination is used as data or information to analyze DSS model.On the other hand,DSS development used structured system developing methodology