This paper provides a methodology of Supplier Quality Performance Assessment (SQPA) for the industrial computer industry that introduces modified Importance-Performance Analysis (IPA) which uses the multiple regression analysis and Decision Making Trial and Evaluation Laboratory (DEMATEL) technique  and creates value for all members through optimizing order-winners and qualifiers to promote supplier quality improvement and solve complex problems using the cause-effect relation. The techniques used in SQPA activities are easily understood. A case involving an industrial computer manufacturer is illustrated to show the benefits of our model