Mapping a process enables a greater understanding of the work, and is standard to evaluate and improve a process. This thesis is conducted at Test Bed Mechanical Design at Scania in Södertälje. Test Bed Construction is a complex process, characterized by a large amount of creative work, technical challenges and coordination between different people and different organizational functions. The aim of the thesis was to identify the Test Bed Construction Process and to develop a visual model of the workflow that also served as support for the engineers in their daily work. During the mapping process, comparisons were made with previous research in lean product development to identify process improvement. A literature review on process mapping and process visualisation resulted in a method for process mapping. The study showed that research on process visualisation is neither structured nor well defined. Nevertheless, there are attempts to create a framework to facilitate the selection of modelling technology. The framework used in this thesis categorizes modelling techniques according to the purpose of the model and the models change tolerance. The literature review also led to the identification of a number of success factors for lean product development. A qualitative case study on UTTD mapped the Test Bed Construction Process as well as the engineer's experiences of their work process. The study resulted in a flow chart of the Test Bed Construction Process and a number of areas where the process could be improved. The process improvements essentially related procedures for documentation and coordination.