The Application Of Network Scheduling In The Highway Engineering Production Organization System

Since the sixties Network Scheduling has extensively applied to the production and practice in our country, because highway is a man-made building and construct production through designing, constructing, consuming many labors materials and machines, so it has peculiar one's own technology economic characteristic, so the importance of the application of network scheduling in highway engineering production organization systems, had been recognized. The network scheduling needs optimization before making it put into effect, in order to abundantly consider the labors, materials, funds and arrange reasonably time problem, fund problem, resource problem, engineering management problem. There are many criteria, for example, time limited for a project, cost, quality, profit, resource, in evaluating the good or bad of the network scheduling. In the past the optimization of network scheduling usually considered one or two criteria in practice, although now there are many compressive optimization models and many optimization under multi-goal conditions, which only consider time limit for a project and cost, time limit for a project and resource, the single relation between quality and cost, or only consider the relation between time limit for a project, cost, resource, and omit construct quality. From the view of the optimization methods, these methods confined to the optimization under singular-goal condition, there are no models which compressively reflect mathematics model of these goals in all-round way, so the research in this respect is feasible .necessary that having great significance too.Generally speaking, a good network scheduling should extensively consider time limit for a project, cost, resource, quality and so on indexes, so this paper sets up multi-goals model and comprehensively evaluate model for single network ,of the multi-goals model this paper sets up three double-goals model, for example, time limit for a project-cost model, resource limited-shortest time limit for a project model ,time limit for a project-quality model. The common method in time limit for a project-cost model is advance gradually method ,which has many advantages, for example, simple, ocular and apt to understand, but the method has amount of calculation heavily and superfluous shortcoming, especially as the construct scheduling network is more complicated and has many critical paths .When there is one critical path ,this paper uses the advance gradually method ,when there are above two critical paths ,this paper uses the theory of max-flow and min-cut .through seeking the min-cut, meantime gains a time limit for a project, abbreviating it for T1; in addition this paper makes use of the resource allocation of the Heuristic Algorithms in the resource limited-time minimal model , gains a time limit for aproject, abbreviating it for T2; last this paper sets up the time-quality model, meantime gains a time limit for a project given a relative quality value, abbreviating it for T3. Based on the study of the construct network project, comprehensively evaluate model poses a new estimate criterion: construct quality and comprehensively consider time limit for a projects cost , resource , quality. Based on T1, T2, T3,, through making using of the method of system synthesis evaluation this paper gains a time limit for a project, abbreviating it for T. Furthermore this paper sets up multi-goals model and comprehensively evaluate model for multi-network. The foundation of multi-goals network model is from the point of view product organization while the foundation of comprehensively evaluate model is preceding double-goals model, comprehensively evaluate model revaluate the network through reconsider time limit for a project, cost, resource, quality.