22Purpose Start-ups are companies that are not yet embedded in a pre-existing network of relationships.
23Studies that researched how start-ups act in their relationships focused on just one type of action and 24 assumes that start-ups are autonomous in how they choose to act. However, organisational action in 25 relationships is both interactive and dynamic. Therefore, the researchers aim to investigate how a start-26 up does interact with its partners over time.
28Design/methodology/approach The research aim is addressed through a longitudinal case study of a 29 start-up in the medical device business. It was analysed how this start-up and its six key partners acted 30 and reacted during 18 interactions episodes, what triggered these actions and what the outcomes of 31 their actions were. In addition, the researchers explored if and how the subsequent episodes were 32 related. 33 34Findings Firstly, the case shows that the past and the future affect current episodes. Secondly, it 35shows that action was triggered by both internal and external events which could expand or constrain 36 opportunities for future interactions. Thirdly, the findings show that there was a pattern in the 37 interaction modes used during the relationship. Fourthly, the findings show that the initial mode of 38 interaction was often imitated by the counterparty. Finally, it is shown that there are clear links 39 between the trigger, interaction process and outcome in an interaction episode. 40 41Research implications The results indicate that besides the focal firm, partners should always be 42 actively and directly involved in any research into organisational action. Moreover, action in 43 relationships should be characterized as a dynamic process that is in a state of continual change.