Study On Network Planning Considering The Resource-dependency

With the use of network planning in project, it has been discovered that the float and the critical path which generated by traditional CPM techniques have a lot of difference between the real project. The mainly reasons are that resources required by activities are unlimited and activities in different path are irrelevant in the scheduling and computation of network planning. In most actual construction projects, resources are highly limited, so the traditional CPM techniques cannot calculate the correct total float and the right critical path.Considering the deficiency of traditional CPM techniques, various resource constrained models have been developed to apply resource availability into scheduling process, in which the resource-constrained scheduling (RCS) model proposed by Wiest is more representative. The model considers the resource which is constrained in project, but the resource dependency is omitted in the backward pass, so the late time of an activity that has resource dependency can be greater than the real value, the total float shall be increased in the difference. Furthermore, the increased total float or the late time could affect predecessors depending on the network condition. Then, most critical activities become non-critical, the critical path is broken (not continuous) and most total float values contain phantom floats.Resource allocation takes very important part in actual project management. And the effective utilization of resource is involved the correlation of activities in different path. Full consideration the resource transfer and effective usage is much significance for assuring project schedule and improving project management level.In this paper the RCS model is improved considering the resource dependency. The improved RCS model can identify total floats and critical paths in a project scheduling with limited resources. The resource-link will be found and network sensitivity also will be analyzed. Analyzing the result of the real project which is calculated by RCS model and improved RCS model, it is found that the improved RCS is more reasonable than the RCS model, so the project manager can plan and control the project more actively and efficiently.Also, activity-on-arrow-network (AOA) is widely applied in project of China, but the existing methods of drawing network graph are more complicated and have many insufficiencies, so it is necessary to need a new method which is easy to understand and to draw network graph of AOA. In this paper, the particle swarm optimization (PSO) algorithm will be imported into the graph drawing of AOA, and corresponding optimized model is established. This model makes the result more reasonable and provides a new path to draw network graph of AOA.