Construction Cost Risk Analysis In The Biding And Construction Phases And Countermeasure Study

The realization process of construction project is different from that of general product, because it is carried out in internal and external environment relatively filled with lots of uncertainty and risk factors, which determines that construction cost is volatile in the implementation process. In order to save investment and improve the benefit of investment, cost management has became scholars'study hotspot in recent years, consequently, a lot of more mature cost management theories come forth. Meanwhile, the project risk management theories and methods also gradually mature. But the root cause of construction cost fluctuating lies in the existence of uncertainty and risk, therefore, by combining risk management with cost management and integrating them, it becomes more according with the requirements of investment control, also, a very good idea to solve uncontrolled investment fundamentally was provided.The bidding phase and construction phase have been chosen as our research focus from the owner's angle in this paper. Construction theory cost can be calculated through earlier-stage planning and design, however, due to affected by a lot of uncertainty and risk factors in the bidding and construction phases, the final real cost often deviates from expected theory cost. From the perspective of risk management, by identifying and assessing the factors of risk that affect construction cost in the bidding phase and construction phase, corresponding countermeasures were put forward in this paper, hoping to improve the level of cost management.By searching a large number of documents, combining them with myself' practical experience, and consulting relevant experts in depth, the factors of cost risk in the bidding and construction phases were further analyzed. The first part is exordium, mainly introducing the background and significance of the topic selected, current research at home and abroad, main contents and innovative points. The second part detailed introduced components of construction cost under the quantity bill-based valuation, providing theoretical basis for the next research, and summarized the characteristics, objectives and contents of construction cost risk, based on this, the application of WBS- RBS method identified the cost risk of bidding and construction phases, and made a further explanation. The third part analyzed the feasibility of construction cost risk assessment based on cloud mode by the theory introduced, and verified that it was some practical value and guidance meaning in practical projects through a case. Corresponding countermeasures were put forward in the fourth part according to the analysis of construction cost risk in second and third parts.The application of WBS-RBS risk identification method based on the core project management tool identified the main risks in the bidding phase:bidding documents preparation risk, contract risks, moral hazard and bidding strategies risk, cost risks in the construction phase are mainly engineering change risk, claims from contractors risk, force majeure risk and staff risk. Secondly, when the factors of cost risk assessed, the two features of risk randomness and fuzziness were integrated researched by applying cloud theory, realizing the conversion between qualitative concept and their quantitative expression, and compensating for the study inadequate of randomness and fuzziness of risk isolated in traditional methods, which is also the main innovation of this paper.Through analysis in the second and third parts, the cost risks are mainly bidding documents preparation risk, contract risk and bidding strategies risks in the biding phase, and engineering change (especially the design change) and claims from contractor are important risks which should to be controlled in the construction phase. Finally the corresponding measures were proposed.