Project portfolio designing is a dynamic multi-criteria decision-making problem under risk. The paper presents an approach for dynamic project portfolio management based on the Analytic Network Process (ANP) model. The ANP model consists of four basic clusters (projects, resources, criteria, time) with their elements and influences. An important factor of the proposed ANP model is time. The ANP method is suitable for the determination of priorities in network systems where there are different types of dependencies between the elements of the system. In each time period, the portfolio of projects is reviewed in line with the strategic objectives of the organization. Management may decide to initiate new projects, but it is not so easy to predict what new projects will appear in the future. The organization must decide under risk whether to assign all available resources to present proposals or to reserve a portion of the funds unused for some time and wait for better alternatives that may occur later. We propose to use a decision tree with multiple criteria and interactive multi-criteria analysis for solving this problem.