Abstract
The Purpose of cost Planning at the early Phase of construction Projects is to provide the clients with the appropriate cost information during the design decision-making process. Therefore, the cost planning process is expected not only to predict projects' cost accurately but also closely to coordinate with the design decision-making activities. This paper proposes a new cost planning method for the effective and efficient directions relating a design decision-making process. Strategies for this method are i ) to utilize elemental cost breakdown system, and ii ) to apply probabilistic distribution theories. Based on these strategic direction, this paper proposed a probabilistic cost planning model for high-rise office building projects. The suggested model provides appropriate cost information to meet clients limited budget and various project' requirements during the design decision-making process. This study is based on probabilistic distribution variables theories and the range estimating technique. This study also develops a web-based software program in order to apply the proposed cost planning model effectively in high-rise of office building construction practices.