3d Modeling and Real-time Monitoring in Support of Lean Production of Engineered-to-order Precast Concrete Buildings

Previous research has highlighted the efficacy of the application of lean production principles in the precast concrete industry. The work also highlighted the dependence of engineered-to-order prefabrication in construction on both engineering and on process control information for production in construction. In current practice in most precast/prestressed plants in the US, producers typically fabricate pieces well in advance of their erection on site, resulting in relatively large buffers of product stored in extensive yards. This practice is generally attributed to the fact that precast production rates are significantly slower than erection rates, and to erratic demands for product from the erection process. The behavior is reinforced by the industry-wide willingness of building clients to pay up to 90% of the cost of precast products on production, rather than on delivery and erection. However, other factors prevent reduction of inventories: among them are the inability of current numbering methods and information systems to support long term erection sequence planning; the high cost and imprecision of real-time feedback (pull) information from the site and/or project management; and producers’ unreliability in identifying and shipping pieces on time from yards that are difficult to manage due to their size. We propose that resolution of these problems requires concerted application of lean principles, of advanced information technology and of real-time monitoring (using Automated Project Performance Control technologies). The potential of information systems and interpreted monitoring data to support a lean production and delivery cycle for precast construction is explored in relation to each of the problems stated.