Cost Estimation Model Using Modified Parameters for Construction Projects

Table 1

Item simplification.

Step	Contents	Method	No. of items	Specifications
1	Investigating the no. of items	Analyzing bill of quantities	24	—
2	Grouping items	Concrete, forms, steel bar, and other	24	No. of items: concrete (5), forms (6), steel bars (7), and other (3)
3	Selecting a unit cost application	Concrete, forms, and steel bar: quantity based; other: cost based	21	Cost ratio: concrete 24.88%, forms 49.73%, steel bar 25.17%, and other 0.22%
4	Item simplification	Integrating items which have similar unit costs	15	Ratio of unit cost error: 180 concrete (2): 1.42%, steel bar (6): 1.56%
5	Exception of items estimated by automation	Concrete pouring and steel cutting	12	Concrete pouring = concrete × 1.01; Steel cutting = steel bar/1.03