Study On Estimation Methods Of Constructional Engineering Cost

This work is supported by a key technology research project in Chongqing entitled"Research on Forecast Model and Network Application to Construction Cost Index System in Chongqing"(No. 17 in [2005]). The basic theory and application on forecast of constructional cost index are studied. The main studied object is the research of time data series by modeling technology from gray system theory. The contents of this paper mainly include the following parts:(1) The common forecasting methods are introduced and discussed in detail;(2) The research progress on forecasting models of constructional cost in domestic and overseas regions is reviewed;(3) Based on the analysis to advantages and disadvantages of various forecasting methods, modeling technology from gray system theory is selected to forecast and model constructional cost in the region of Chongqing;(4) From the point of view of systems engineering, the system attribute of constructional projects is analyzed, the basic methods on system modeling are dealt with briefly, and the modeling technology of constructional cost in Chongqing is determined;(5) The modeling idea and the forecasting steps from gray technology are presented;(6) The modeling and its solving from gray technology are improved, mainly including the improvement of model GM (2,1), the solving of model GM (1,1), GM (2,1) and model Verhulst by least-squares method;(7) Aimed at the characteristic of observed data sequence, the forecasting of data sequence with mutation and the modeling method of non-equidistant data sequence are researched;(8) In order to facilitate the establishment of network applications, the theoretical check examples, which are from actual projects as far as possible, are presented for a variety of models;(9) The concrete modeling processes from gray system is presented.(10) In view of the complexity of data distribution and the difficulty of modeling technology from gray theory, the modeling processes of ARMA is given; (11) The research trend of cost forecasting based on gray system is put forwarded.