The Research On Fuzzy Network Planning Technology And Risk

Network planning is an effective tool in project planning and schedule control for it can reflect the actual situation better, in which the fuzzy network scheduling techniques has an important guiding role to identify the improvement programs and the rational use of resources. Risk of progress study could clear the risk of schedule to achieve, and taken measures to ensure the successful completion of the project objectives on schedule. In this thesis, fuzzy theory is introduced to the network plan, and the progress of computing technology and its application in project is mainly studied.Firstly, the time parameters of fuzzy network planning is calculated by application of the fuzzy mathematical theory, taking into account that the fuzzy number may be negative or fuzzy distribution is no-convened and other non-frivolous issues are appeared if using the traditional Minkowski subtraction to calculate the time difference in fuzzy network planning, a new linear programming model is established so as to ensure that the fuzzy time parameters are always positive and convex.Secondly,for the different lines in practical engineering applications, the critical path couldn't be determined by the traditional method, especially it is very difficult to identify a line is the key route or not, in this thesis, an improved lattice nearness method is proposed so that a theoretical basis is provided for the determination of critical path in fuzzy network planning.Thirdly, for the subjectivity problem of schedule risk in fuzzy network planning, the completed risk of each work is calculated by the information entropy theory, then, it should be focused on the higher risk work. For the study of completion probability in the prescribed time, the influence of both the randomness and fuzziness to the total duration which in uncertainty are take into accounted generally, the fuzzy completion probability is calculated by the combining method of fuzzy probability theory and fuzzy entropy theory, from the calculation results, it can be concluded that the method introduced in this thesis is more in line with the actual situation of the project.Finally, the thesis takes the mine construction of Hujiahe mining in Binchang area in Shaanxi as an example, the calculation of fuzzy time parameters, the determination of fuzzy critical path and the analysis of fuzzy schedule risk are studied respectively, and the effectively of the method introduced in this thesis is proved well.