Project Schedule Management Research Based On Critical Chain Method

Process management is one of the most important contents of project Manage, and it is aseries of project management processes to ensure the project completed on time eventually. Itsimportant goal is to ensure that the project can complete the task within the stipulated time.But the traditional schedule management (CPM, PERT etc.) has some shortcomings: activityduration estimates is too long, overlong duration estimation has rarely been completed aheadof schedule, process completed ahead is very difficult to be used efficiently, line merged andthe parallel task to bring delay, progress plan without considering resource conflicts andactivity duration did not consider the behavior and psychological factors of the human,because of which the critical path is changed and not easy to grasp the key, and safety time iswasted. Eventually, it appear some static duration management status which is time-delay, anda waste of resources,and difficult to control schedule effectively. Critical chain method isbased on the schedule management method of the theory of constraints. The method not onlyconsider the logical relationship between the processes, also consider the resource conflictbetween the processes. It concentrates the safety time on the end of the critical chain as abuffer unified management, to avoid wasting time. The bottleneck resources are set asideenough time to prepare, avoiding resource conflicts phenomenon. It even consider thebehavior of human factors, arouse the enthusiasm of staff, and help to improve the workefficiency. Therefore, CCM can make up for the deficiencies of the traditional schedulemanagement method.Firstly, this paper discusses the duration estimation method and schedule representationof the general project progress. It mainly analyzes the application method, the characteristicsand theoretical defects of CCM. Secondly, on the basis of TOC, the convergence theory andcentral limit theorem, this paper proves the possibility that CCM can shorten the duration ofmaking schedule plan.and it analyzes the subjective reason of the delay of construction date.Through identifying constraints, identifying key chain, eliminating the safety time, insertingbuffers and other steps, CCM plans the duration of the project. Through monitoring the buffer,CCM ensures that the project is completed on schedule in the implementation process. CCMstressed the project’s overall optimization, rather than local optimization. Finally, this paperconstruct the project schedule management framework based on CCM. The project schedulemanagement is divided into four stages,including project launch, project schedule, progresscontrol and project ending. In the progress of planning stage, project plan is made based onCCM of the fuzzy-distance comprehensive evaluation method. The duration is firstlyestimated with whitening weight function deformation after to take a trapezoidal fuzzynumbers of certain truth degree for each process. And then uncertainty of the process is detemined with distance comprehensive evaluation method. The scheduled time and safetytime of each process are calculated according to estimating schedule and process uncertainty.The safety time of each link is taken together, and the corresponding buffer size is calculatedwith the root variance method. In the progress of control stage, the traditional "three-color"buffer management method in practical applications sometimes can not reflect the realsituation of the project, leading managers to make wrong judgements. In order to avoid theinconsistent phenomenon between workload and the completion of the project bufferconsumption, the buffer is divided into three parts based on the uncertainty of each process. Inthe process of construction, monitoring of the buffer reach in each process, no longer in thewhole project buffer. This method is more conducive to the buffer management, and moreeasier to find out the process of causing construction schedule delays. Therefore, dividing thebuffer according to process uncertainty and managing buffer with relatively small units aremore effectively, and more in line with the actual situation.In the case of residential buildings in Huimin County Dragon Bay District Civil AffairsBureau1#, when the original schedule encountered delays, the construction schedule of theremaining processes are re-plan with the process time estimation method, the size of thebuffer design methods and schedule monitoring method. In the case of the consstructionperiod delay, residential buildings are completed ahead of schedule. Through the analysis ofexample, the feasibility and practicability of the project schedule management are verifiedbased on CCM of the fuzzy-distance comprehensive evaluation method distance evaluationmethod.