Research On Early-Warning Of Project Schedule Risk Based On Network Planning Technique

Schedule objective of project is one of the three objectives of project management, the quality of progress is related to project's success directly, but the risk of project schedule will postpone the time limit for a project, even affects the smooth implementation of a project. Therefore, it is necessary to carry on risk management in project schedule management, Whereas, the risk analysis technology & method as well as the risk management system have not achieved mature level in the area. It is significant to the projects that both make further research & exploration on schedule risk management and estimate the schedule risk effectively.Network Planning Technique is very important in project schedule management, However, The uncertainty factors influenced project schedule are multitudinous and complex, and each uncertainty factor has different effect on certain project. The traditional Network Planning Technique neglected or simplified these elements of uncertainty, which caused biggish deviation in certain actual schedule project management. In order to enhance the practicability & control function of Network Planning Technique, the thesis took the uncertainty factors into account, applied Probability Statistical Theory to analyze the entire network planning, which was significant to the research of project schedule risk problem.This thesis introduced the theory of early-warning management about project, elaborated basic principle of project progress management,the system of risk management and the skeleton of risk analysis. Summarized the theory of early-warning management, illuminated the relations between early-warning and risk management of project schedule. Then introduced the principle,characteristics of network-based planning techniques, elaborated the application of network-based planning techniques in project schedule management, probability theory was used to elaborate the problem of probability distribution about time limit for a project of working procedure and the total network duration, Studied the issue when the variance of uncritical path was bigger than that of critical path, the magnitude influence to critical path made by uncritical path, estimated project schedule through Central Limit Theorem. According to the research, the thesis put forward schedule risk precaution model and strategy to reply risk, selected the current progress deviation ratio of test point (α_i) and dynamic goal time limit for a project deviation ratio (β_i) as early -warning target, considered the different factor influence, carries on revision to the target, and unifies the example to carry on the confirmation.The concrete research of this thesis's content is as follows:(1) Primary content of network planning techniques & project schedule management were researched in this thesis, the application condition of network planning techniques in project schedule management was analyzed.(2) It brought forward the insufficiency that PERT applied in management, elaborated the fundamentality of project schedule risk management, further analyzed the risk factor influenced project progress, and analyzed how risk factors affected project schedule concretely. Then, Probability analysis were introduced to estimate project period, studied completion probability & variance of critical path and uncritical path in classic PERT network, thereby determined critical path and uncritical path further. Analyzed risk factors that influenced project progress further, and analyzed concretely how risk factors affect project progress, simultaneously carried on quota &qualitative appraisal to risk factors.(3) It discussed the early-warning concept, constructed the whole structure of risk early warning management system, Proposed the risk early warning analysis method, selected the reasonable risk supervision point, set up corresponding risk early warning index. Then established early warning model, gave the early warning benchmark by quantification form, carried on graduation to it, gave different early warning signal, and applied the model in case to confirmation the effect of schedule risk precaution. Finally, suggested measures to prevent schedule risk.