The viewpoints of multiobjective, satisfactory solution, reality and flexibility for solving systems problems are philosophies of the GP methodology. Based on the philosophies, the present article explains the concept of basic model (BM) and transform from BM into conventional linear programming and multiplexmodel of lexicographic multiobjective linear programming. It also points out the effects of assumptions on validation of model in the transforming. The linear goal programming with weights, fuzzy programming, linear multiobjective programming with nondominated solutions and various forms of multiobjective mathematical programming may be placed into the multiplex formulation.