Personal software process

They can evaluate their work and suggest improvement direction by analyzing and reviewing development time, defects, and size data.

"Personal Software Process" and "PSP" are registered service marks of the Carnegie Mellon University.

Humphrey encourages proficient engineers to customize these scripts and templates as they gain an understanding of their own strengths and weaknesses.

Based upon the baseline data collected in PSP0 and PSP0.1, the engineer estimates how large a new program will be and prepares a test report (PSP1).

Engineers learn to evaluate and improve their process by measuring how long tasks take and the number of defects they inject and remove in each phase of development.

The PSP has four core measures: Applying standards to the process can ensure the data is precise and consistent.

The PSP also uses statistical techniques, such as correlation, linear regression, and standard deviation, to translate data into useful information for improving estimating, planning and quality.

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.

[4] 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.

However, the TSP/PSP differs from Agile in its emphasis on documenting the process and its use of data for predicting and defining project schedules.

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.

Historical project data, which exposes where time is spent and defects introduced, help developers to identify areas to improve.