Definition:
The Personal Software Process (PSP) provides engineers with a disciplined personal framework for doing software work. The PSP process consists of a set of methods, forms, and scripts that show software engineers how to plan, measure, and manage their work. It is introduced with a textbook and a course that are designed for both industrial and academic use. The PSP is designed for use with any programming language or design methodology and it can be used for most aspects of software work, including writing requirements, running tests, defining processes, and repairing defects. When engineers use the PSP, the recommended process goal is to produce zero-defect products on schedule and within planned costs. When used with the Team Software Process (TSP), the PSP has been effective in helping engineers achieve these objectives.
Further Reading:
Book: Agile Software Development by Dr. Alistair Cockburn.