Automated Interactive Cost Estimating System for reinforced concrete building structures.

Abstract

Architectural and engineering decisions among design alternatives at all stages of design should be based on accurate cost information. Currently, numerous cost estimating systems are available in the construction industry, but none of these enable the architectural engineer to check the detailed construction cost during the design process. This research develops a cost estimating model that provides detailed cost information on design alternatives at all stages of design. The model, called the Automated Interactive Cost Estimating System (AICES), is implemented for reinforced concrete building structures. AICES gives the users access to reinforced concrete cost information that is sensitive to variations in architectural and engineering design, allowing them to make intelligent design decisions. The core of AICES is automated design and detailed cost estimating of prototype structures based on input from more general design. Design is developed through a hierarchical design modification process at schematic, preliminary, and detailed design levels. Design input at each level produces a usable detailed reinforced concrete structural design that is itself input to automated detailed estimating. This provides accurate, realistic detailed estimates of costs for alternative values of design variables. AICES is composed of databases, a knowledge base, and application programs to support design modification and perform detailed cost estimating. The databases consist of a project-independent database containing the generic information, and a project-dependent database storing the specific information for a project. The databases are linked by key items to provide default detailed designs and perform detailed cost estimating. The knowledge base consists of rules that represent construction knowledge to guide the user in selecting a suitable construction method. The implementation programs are coded in a relational database software and a rule-based expert system package. This research contributes to the integration of design and construction by linking the cost estimating process to the design process. It also contributes to the development of a design and cost estimating system by establishing a project database in which the design and estimating data are efficiently retrieved and used.