Software process improvement (SPI) research and practice is transforming from the traditional large-scale assessment based improvement initiatives into smaller sized, tailored initiatives where the emphasis is set on the development personnel and their personal abilities. The personal software process (PSPSM) is a method for improving the personal capabilities of a single software engineer. This paper contributes to the body of knowledge within this area by reporting experiences from Denmark. The results indicate an improvement in the effort estimation skills and a significant increase in the resulting product quality in terms of reduced total defect density. The data shows that with relatively small effort (i.e., 10%) used in defect prevention activities (i.e., design and code reviews) almost one third of all defects were removed and consequently the time required for the testing was cut by 50%. Based on this data the use of the PSP method in the software industry is discussed.