① Integrity principle

② relevance principle ③ orderliness principle ④ dynamic principle ⑤ optimization principle 3. Hall three-dimensional structure: the working process of system engineering is investigated from three aspects of logic, time and knowledge. 1) Three tools of logic dimension: logic reasoning, probability statistical reasoning and fuzzy mathematics 2) time dimension 3) knowledge dimension

4. The risk value (itemized risk) of the item can be obtained by multiplying the factor and the coefficient of the item in the project risk assessment