This study aims at creating an Operating System (OS) selection framework for decision makers (DMs). Since DMs have to consider both economic and non-economic aspects of technology selection, both factors have been considered in the developed framework. The economic part of the decision process has been developed by Fuzzy Replacement Analysis. Non-economic factors and financial figures have been combined using a fuzzy analytic hierarchy process (Fuzzy AHP) approach. Since there exists incomplete and vague information of future cash flows and the crisp AHP cannot reflect the human thinking style in capturing the expert's knowledge, the fuzzy sets theory has been applied to both AHP and replacement analysis, which compares two OSs with and without license, respectively. A real numerical application has also been demonstrated. Both the theoretical and the practical background of this paper have shown that fuzzy AHP and fuzzy replacement analysis can cover the uncertainty of assigning crisp concepts in related investment decision-making topics. (c) 2004 Elsevier B.V. All rights reserved.