Software process improvement is a complex and expensive endeavor requiring extensive resources and long term commitment. In the present study software process improvement (SPI) problems in small organizations were tackled by dividing the overall effort into three subtopics: technical infrastructure, working practices, and management infrastructure. Partitioning the SPI efforts into these three subtopics makes it apparent that all of these topics do not need to be tackled in the same way but some tasks can, e.g., be outsourced. In this paper the results of an investigation into the use of the model above in requirements engineering (RE) process improvement are reported from three industrial case studies. A domain specific method was constructed independently of the utilizing companies, i.e., outsourced, and it was then used in SPI efforts in the companies to establish a solid infrastructure for basic RE in a short period of time, with limited resources, and without previous expertise in RE. It is argued that the suggested partitioning can both lower the threshold for initiating software process improvement efforts in industry and increase the likelihood of successfully completing them.