The objective of this thesis is to investigate the role that business networks have in the internationalisation process of a Finnish software service firm entering to Sweden. To achieve this goal, the ARA-model was used as a theoretical framework. This thesis focused only on the positive network functions affecting the internationalisation of the case company. The selected research strategy for this thesis is a single case study. The data collection was conducted with three interviews. The interviews were semi-structured themed interviews. ARA-model proved to be useful in describing internationalisation of a Finnish software service firm, Futurice. It helped to show that the business networks had a major positive impact for the internationalisation of Futurice. It was evident that certain key actors, especially key individuals, had the greatest positive impact for the internationalisation. This impact was achieved through their network relationships and through their knowledge about these networks. These networks and network relationships were mainly used to find potential new customers, to gain better positions in existing customers, to find new specialised recruits and to gain better position in the market. To put short, networks were used to overcome limitations and to mobilise resources that Futurice needed. Findings suggest that resources related to knowledge, experience, and skills (KES resource) are key for success. Most important activities were related to networking, sales and recruiting. Management should focus on leading these activities and resources and they should be closely monitored and quantified clearly. Especially activities related to networking should be emphasised. Main suggestions for further research are to add time dimension to ARA-model, conduct similar study for other firms and conduct research which focuses or incorporates the possible negative effects of networks.