Abstract: Based on the information entropy theory, the effect of twofactor relation of processes on a process system is analyzed. The concept of process entropy is firstly introduced and an accompanying quantitative research model for business process reengineering is established. Four hypotheses  for process factors relation research are put forward in this study. The detailed calculation steps of process entropy are provided. From the standpoint of the entropy difference before and after an improvement of process system, the necessity for business reengineering is given. Meanwhile, the general methods for improvement of the process system are discussed. A case study is included to demonstrate the feasibility and effectiveness of the proposed method.

Key words: business process reengineering(BPR), process entropy, processing factor, factor relation