Editing Personal software process (section)

===Quality===
High-quality software is the goal of the PSP, and quality is measured in terms of defects. For the PSP, a quality process should produce low-defect software that meets the user needs.

The PSP phase structure enables PSP developers to catch defects early. By catching defects early, the PSP can reduce the amount of time spent in later phases, such as Test.

The PSP theory is that it is more economical and effective to remove defects as close as possible to where and when they were injected, so software engineers are encouraged to conduct personal reviews for each phase of development. Therefore, the PSP phase structure includes two review phases:

* Design Review
* Code Review

To do an effective review, you need to follow a structured review process. The PSP recommends using checklists to help developers to consistently follow an orderly procedure.

The PSP follows the premise that when people make mistakes, their errors are usually predictable, so PSP developers can personalize their checklists to target their own common errors. Software engineers are also expected to complete process improvement proposals, to identify areas of weakness in their current performance that they should target for improvement. Historical project data, which exposes where time is spent and defects introduced, help developers to identify areas to improve.

PSP developers are also expected to conduct personal reviews before their work undergoes a peer or team review.