Due to liberation of the electricity market and the beginning of the exchange-based trading, a considerable amount of parties have transferred from the traditional fixed price agreement of definite duration to the portfolio-based purchasing of electricity. With the active portfolio management, the channel to the market remains constantly open and the purchase decision can be divided to a longer period, which decreases the dependency on just one moment's price level. The variety of the financial instruments, which are used to fix the procurement cost of electricity, has increased significantly in the exchange and in the OTC-market in recent years. Hereby,the selection of the useable instruments and the argumentation to the customer demands even more attention. The objective of the product management was to create simple frames for the fundamental cases of portfolio management, which can beequipped with different features. With product management, the aim is also to clarify customers' image of available alternatives and to assist marketing. Second objective for this Master's thesis was to develop indicators, by which the customer and the portfolio manager can observe the success of the portfolio management. The indicators were implemented in the Excel-environment and the tested portfolios consisted mainly of the portfolios, chosen for the final stage of the product management. Based on this thesis, the intention is to implement an application to an existing Internet-based portfolio management service, which enables continuous assessment of the success of portfolio management.