The series papers advance and expound the system improvable theory which suit to every complicated system. This paper has discussed the for-mation,application field and significance of PSI.

• 本系列论文提出并论述了适用于各种不同复杂程度的系统的可改进理论PSI;本文阐述了PSI的产生、所解决的问题、涉及的领域及其意义。