Research On The Optimization Methodology For The Key Logistics Problems Of Construction Project

With the raising of construction projects complexity increasingly and the conversion the owners' pursue from low-cost to high-value, fierce competition in the market brings about tremendous pressure on construction project development. Traditional project management mode, which is separated construction phases and is sluggish material and information flow, has become increasingly unable to meet the demands of modernized construction, and reform of construction project management mode has become imperative.A Large amount of construction practices illustrate that the main reasons for delay and overinvestment in construction projects are the unsmooth information flow and obsolete material management. Logistics management concepts and tools currently have a great value for several business sectors that are searching for productivity and competitiveness improvement, providing costs reduction and better customer satisfaction. But the research on it is booming now in the area of construction project. The thesis presents a new optimization methodology for the key logistics problems of construction projects, in which theory on logistics management, operation management, lean thinking and optimization methods are utilized altogether. The improvement on construction project logistics management will definitely be beneficial to enhancing the efficiency of construction projects management.The concept of construction projects logistics is brought forward and its characteristics are determined by compare it with traditional logistics, and a framework model for construction projects logistics management is constructed. Logistics management of construction projects is divided into supply logistics management and site logistics management. The suppliers' pro-active delivery is the key problem of supply logistics management and is studied. The key problems of site logistics management are information flow optimization, planning and its control, dynamic site layout, and they are analyzed. The specific logistics management team is introduced. The key responsibilities of main participants are identified.Information flow of construction project is defined, and its model is constructed. The characteristics of design are determined, which are large amount of information feedback and iteration. Design process is divided into four parts in the flow perspective, and DSM of design process for a construction project is constructed. The improved DSM method is addressed and used to construct information flow optimization model in design process. Construction model based on IDEF0 is built, and construction is indicated as an interacted process of material flow and information flow. Real time transmit of information is realized by the integrated wireless and visual system based on internet (IW&VS-I), constructed by author, thus, to optimize information flow in construction.The concept of material flow for construction project is address based on lean thinking. Introducing the most advanced tool of lean construction abroad, which is Last Planner System deeply, the shortages of CPM and PERT is pointed out and the advantages of LPS are nailed down. LPS is improved further, and construction schedule is divided into master plan, phase plan, lookahead plan and weekly work plan on it. Material requirement plan, which are divided into supply plan, request plan and daily delivery plan, is produced based on it, so purchase driven by construction is realized. This will optimize construction material flow fundamentally. Proper work structuring is designed, and it is utilized to control weekly work plan together with four kinds of constraints, which are contract, engineering, resource and design. The reliability of schedule system is measured and improved by percent plan complete (PPC). Also, outsite production is put forward, and its realization is studied on. Introduce and establish Kanban system fitting for construction site to optimize material flow.Genetic Algorithm is introduced to optimize site layout problems of construction projects. Integrated Genetic Algorithm model for construction site layout optimization is constructed, and a program is developed to implement the GA system. The site layout problems and their features are determined. Also, the applicability of GA for construction site is analyzed. Both of horizontal and vertical travel is considered in the model. The above IW&VS-I and material requirement plan produced on improved LPS are linked with GA, and setup and dismantling cost of temporary facilities are determined to realize dynamic layout of site. In the end, an empirical study is presented, and it verified the feasibility of the above methods.