In the beginning of 2014 the International Standard Organization launched the first version of the ISO 55000 series on asset management, which describes the requirements for an asset management system. The ISO claims important benefits for organizations implementing the ISO 55001, but empirical research to support these claims is lacking. This research establishes the most important impact factors of an AMS in terms of the positive and negative effects of the system. Also, the research provides insight into what is to be expected from the implementation of an asset management system in terms of the challenges and critical success factors. Finally, the research attempts to determine what specific aspects or company values of an organization are influenced by the AMS. The main research question was formulated: “How to create insight in the impact of implementing an asset management system (AMS)?” Based on extensive literature study on the impact of management systems in general and a context study of the sector of power and gas grid operators, the term impact has been defined as the influence of impact-factors in five categories (motivations, challenges, positive and negative effects and critical success factors) on four general company values for grid operators (reliability, safety, public image and regulatory requirements) and on three preconditions for existence of almost any organization (employee satisfaction, organizational effectiveness and financial efficiency). Possible impact factors have been identified from the literature study and provided the input for a questionnaire. Triangulation of results from semi-structured interviews with Dutch grid operators, Dutch survey respondents and foreign survey respondents produced lists of most relevant impact factors of implementing an asset management system for operators of power and gas grids in all five categories. The most relevant positive effects influence the organizational effectiveness of the organization by clarification of roles and responsibilities and improved transparency. Negative effects are the unexpected amount of time and effort and the friction among and double work for staff members due to the restructuring. Working up the quality of data on the assets together with realizing the necessary cultural changes have been the most relevant challenges for the grid operators and therefore effective leadership and ensuring commitment of all employees involved have proven to be the most relevant critical success factors. Overall, the grid operators are satisfied with the impact of implementing the asset management system. Interesting conclusions from these results include that although increases in financial and asset performance in terms of increased reliability and safety as a result of implementing an AMS are claimed by the norms, the results of these research do not unambiguously support these claims. In a next step to quantitatively measure the impact of an AMS, research or organizations should instead focus on measuring the increase in organizational effectiveness, with the reduction of time in management meetings spend on investment decisions and the investments saved or made due to the increased insight into asset-related risks as potential performance indicators. Also, the effect of time on the relevance of positive and negative effects seems limited over a period of about eight years. This might indicate that, due to the long lifetime of the assets in this sector, some effects take even longer to surface. Finally, the research support the claim that Dutch grid operators are relatively mature in asset management knowledge and procedures compared to most foreign grid operators. Most conclusions of this research are based on the perception of representatives of grid operators. As responses to the international survey came from all over the world, differences in definitions of asset management and asset management systems as well as differences in maturity in the concepts will have influenced the results. Furthermore, the respondents have positions in different departments and layers of their organizations and will therefore have rated impact from different perspectives, which will have also influenced the outcomes. Finally, the interviewed asset managers are promoters of the systems within their organization and might therefore be somewhat biased in assessing the relevance of asset management systems. Because of these reasons, the results and conclusions should be adopted with care. As the results point out that the positive effects of the system mainly influence the organizational effectiveness, which is an aspect that is mainly used by public organizations (Richard et al., 2008), further research should focus on the commercial impact of the system. Applying a similar methodology in a more private sector will create insight into the commercial value of an AMS. Also, in order to substantiate the findings in this research, further research should focus on analyzing statistical data. Because of the public character of the sector, a lot of data on the performance of the grid operators is available and analysis of this data could provide an objective contribution to assessing the impact of asset management systems.