Study On Project Scheduling And Resource Optimization In Highway Construction Based On Petri Nets

Based on the analysis of the limitations of the traditional project scheduling and control methods in highway construction, for example, difficulty in work detail breakdown, difficulty in schedule adjustment, coarseness in resources requirment estimation and incapacity for construction management, a method based on Petri Nets modeling and simulation is put forward for project scheduling and resource optimization in this dissertation. The modeling method of Petri nets for construction procedures, project scheduling, risk analysis, resource optimization, dynamic project scheduling methods are studied in this paper.In the study of Petri nets modeling method for construction procedure, this paper introduces the Object-Oriented Petri Nets into construction field for the first time. According to schedule and resource goals, taking into account project costs, the modeling method of resource, construction process and time are studied. A hyberarchy model of highway construction simulation is put forwords. The form, paramentric estimation as well as sampling methods of activity duration distribution are discussed widely, and also the influence of construction negative factors to activity duration is studied.In the project scheduling study, the algorithms of Simulation Critical Path (SCP) and Activity Criticality Probability (ACP) in Petri Nets are deduced based on incidence matrix. For the first time, the algorithms of activity time parameters in simulation are given, it solves the problem that simulation technology in project scheduling can't produce activity time parameter to manage project.In project risk management, the significations and algorithms of Activity Cruciality Index (ACI), Reference Point Completion Probability (RPCP) and project period risk in Petri Nets are studied. RPCP is presented for the first time in this paper. It can conform to engineering better than completion probability which only use the completion time as a reference point. Furthermore, schedule adjustment is discussed based on RPCP.In the study of resource optimization, the bottle-neck identification method of resources in construction localness is studied. Four kinds of resource boltle-neck estilimation methods are proposed. In general optimization, an improved minimum variance method has been brought forward and compared with the example in literature.