Application of OLAP information model to parametric cost estimate and BIM

Abstract

The purpose of this study is to develop a parametric cost estimating model for the early design stage using the OLAP (On-line Analytical Processing; Multi-dimensional Query System) based on quantity case data related to architectural design features. The OLAP system defines architectural design features as parameters that are factors for change in volume of quantity, and these can be used to query quantity information. The parametric estimating model can also evaluate the cost for various alternative designs by utilizing design features as the parameters. The parametric cost model is very highly accurate compared to existing cost estimation methods. The cost estimating process suggested in this study is divided into two stages. The first process involves measuring major quantities based on the design information level. The second process predicts minor quantities that can be used by the OLAP system. In the design development stage, the major quantity items are concrete and forms. The minor quantity items include the ratio of steel (rebar) that must be predicted. In this case study, the steel (rebar) ratio is predicted using the OLAP system in the design development stage.