Estimating the Cost of Strauss Pile Retaining Wall Works Using the Cost Significant Method

Abstract

Cost estimation is an important element in a project. In the early stages of a project, information for estimates tends to be less accurate. Therefore, a cost estimation model is needed that can explain most of the projects based on the lack of information. The estimation method used is the Cost Significant Model. The aim is to determine the accuracy of the Strauss Mast Retaining Wall Work cost estimation model against the actual project cost. Data was collected using the sampling method, and 5 (five) similar project packages were obtained from 2019-2021. Produce 2 (two) Significant Cost Items that have cumulative costs (80%), namely Strauss Pile Work (X3) of 32% and Pile Work (X4) of 48%. Then it is analyzed to produce a regression equation formula using the SPSS application, and the equation is Y = 5696.59+5.270 X3-1,389X4 with a Cost Model Factor of 1.11. Estimated accuracy ranges from -7.3% to +8.4%. With an average of +0%. The accuracy rate is in class 1 of the International AACE classification, which has a lower limit of -3% to -10% and an upper limit of +3% to 15%. The estimation model is feasible to use to check the bid estimate.