I have done usability and user research work for different projects and products. In Nokia Siemens Networks (2004 - 2007) I worked as a specialist in network base station management application development team. The applications were designed as tools for field mechanics and network operators (B-to-B). The functionality of these systems was extremely complex and the operational reliability of network systems was highly important. In this work it was crucial to know who are the users and for which tasks the application is used and needed and what is the context of use. For example these PC apps were used both outdoors, on-the-go and indoors, stationary. With B-to-B products, the user segments are more clear and the users are easier to identify than with consumer products, which can help focusing the product definitions in otherwise very complex application systems.