基于返工成本率、变更成本率、成本超支率3个指标,对181个项目数据进行T检验和方差分析.研究发现,在交易方式方面,与设计-招标-建造方式相比,设计-建造方式能显著降低项目的成本超支率,返工成本率和变更成本率也较低;在支付方式方面,议标总价合同的成本超支率最低,为-1.97%,单价合同的成本超支率最高,为10.70%.综合考虑交易方式和支付方式,采用设计-建造方式、议标总价合同,成本超支率最低,而变更成本率最高,应引起项目参与方的重视.
Based on three indicators of rework cost,change cost and cost growth,data from 181 projects were analyzed through T test and analysis of variance.The results show that considering project delivery method,DB method has a significantly lower cost growth in comparison to DBB method,with a lower rework cost and change cost also,though not significant.In respect of Payment method,cost growth is the lowest in lump sum contract through negotiation with a mean value of-1.97%,and the highest in unit price contract with a mean value of 10.70%.Taking these two aspects into consideration together,projects with DB method and lump sum contract through negotiation have the lowest cost growth,accompanied with the highest change cost,which should draw project participants' attention.