Institute of Transportation, MOTC

　　Transportation programming is the process of selecting and determining a final set of transportation projects, including project evaluation, selection, scheduling and budget portfolio management. Since conventional transportation programming models lacked the consideration for project portfolios and synthetic effects, such important research topics arise as the introduction of a project portfolio management concept, the consideration for benefits, costs and risks of the project portfolios, the establishment of a project portfolio programming model, and the selection of optimum project portfolio solutions. This study developed a project portfolio programming model with project portfolios as the target for decision making rather than individual projects in the previous programming models. Since the programming tasks are filled with uncertainties in terms of benefits, risks and budgets of project portfolios, grey multiobjective 0-1 integer programming problems were designed. Additionally, a grey Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) approach was developed to solve the proposed model. With the large-scale transportation development projects of the Public Construction Commission, Executive Yuan, as the assumption basis of numerical examples and applications, the analysis confirmed the feasibility of the proposed model. The trade-off ratios between two goals were shown using different goal weight combinations for negotiations and decision making in regard to project portfolio programming. The proposed model uses project portfolios as the target for decision making, and can therefore set up a foundation for transportation programming models using a project portfolio management approach. The incorporation of grey numbers in the programming model allows possible ranges for the input values of benefits, risks and budgets, which helps to maintain the flexibility in decision making when planners are faced with and dealing with indefinite conditions for programming.