Editing Personal software process (section)

===PSP and the TSP===
In practice, PSP skills are used in a TSP team environment. TSP teams consist of PSP-trained developers who volunteer for areas of project responsibility, so the project is managed by the team itself. Using personal data gathered using their PSP skills; the team makes the plans, the estimates, and controls the quality.

Using PSP process methods can help TSP teams to meet their schedule commitments and produce high quality software. For example, according to research by Watts Humphrey, a third of all software projects fail,<ref>Humphrey, Watts S. "Why Big Software Projects Fail: The 12 Key Questions." CrossTalk Mar. 2005 http://www.crosstalkonline.org/storage/issue-archives/2005/200503/200503-Humphrey.pdf {{Webarchive|url=https://web.archive.org/web/20191105150756/http://www.crosstalkonline.org/storage/issue-archives/2005/200503/200503-Humphrey.pdf |date=2019-11-05 }}</ref> but an SEI study on 20 TSP projects in 13 different organizations found that TSP teams missed their target schedules by an average of only six percent.<ref>Davis, Noopur, and Julia Mullaney. The Team Software Process SM (TSP SM) in Practice: A Summary of Recent Results. Pittsburgh, PA: Software Engineering Institute, Sept. 2003.</ref>

Successfully meeting schedule commitments can be attributed to using historical data to make more accurate estimates, so projects are based on realistic plans – and by using PSP quality methods, they produce low-defect software, which reduces time spent on removing defects in later phases, such as integration and acceptance testing.