This thesis examines how inter-firm relationships and routines influence the process and outcomes of new service development (NSD). The research questions addressed are: 1) How do inter-firm relationships and routines influence the speed of NSD? and 2) In what ways do the different types of service development affect inter-firm relationships and organisational routines associated with the speed of NSD? Prior research has emphasized the importance of cooperating with other organizations to exploit external sources of knowledge and capabilities, but relatively little is known about the specific mechanisms to achieve this and how these affect the outcomes of new service development. This research contributes to the literature on new service development and innovation networks. The research design consists of comparative case studies and draws on empirical evidence from the development of two contrasting e-commerce services in the four dominant Taiwanese convenience store chains. In total 52 interviews were conducted with members of staff of convenience store chains and suppliers. The interviews were analyzed using the thematic framework approach, which represents the patterns and relationships in the interview data. Cross-case synthesis was chosen as the analytical technique to summarize the findings from the individual cases. The present study found that trust and interdependence have positive influence on the speed of NSD. Intensity of inter-firm collaboration has a negative effect on the speed of NSD under some circumstances (e.g. task complexity and project newness). Moreover, the relationship between organizational routines for knowledge transfer and the speed of NSD may vary under different degrees of project newness. The thesis demonstrates the interaction of organizational and project level characteristics in new service development, and the multi-dimensional nature of service development compared to that of conventional product development.