The building of large scale information systems in healthcare is a current issue in Norway. Such systems are often built as large systems from the start. This thesis studies another approach: small tailored solutions that grow to become large integrated systems. This thesis adheres to an interpretive research approach, and the empirical material comes from the development of an electronic system for general practitioners ordering laboratory services from hospitals. The aim is to provide some detailed empirical insights as well as expand on conceptual perspectives of processes related to expanding small local information systems into large scale integrated systems. The case demonstrated that the first development phases were characterised by a small step and iterative approach where users had an active role and where the technology was developed according to the immediate needs of the users. Later the development was largely influenced by large procurement processes and tenders, and further development and implementation were done in large steps based on detailed contracts. In this transition between small and large scale the conditions for the vendor changed drastically. This thesis will contribute with an understanding of the different actors involved in the building of such systems, and their contributions. The thesis will also contribute to a better understanding of the characteristics of the technology related to the possibilities to make changes in accordance with a changing environment