Using labor productivity data to evaluate the application of lean principles to the concrete construction process

The research uses labor productivity data to test the application of lean construction principles to the concrete construction process. The transformation from traditional manufacturing (most notably mass production) to lean production and eventually lean construction is discussed. A comparison is also made of the manufacturing and construction processes. A three-step process is used to identify the lean principles that are relevant to the construction process. A theoretical lean construction process model is then identified based on this process. The model is also dependent on the hierarchy of construction, which is discussed. To test this hypothetical model, data is collected from five construction sites in Centre County, Pennsylvania. Four of these sites are bridge projects on the Interstate-99 (footers, piers and abutment walls) and one an office building at the Pennsylvania State University. The data collected is limited to formwork, steel re-bar and concrete in footers, walls and piers. After the data collection, concrete processing and analysis involves determining several performance indicators and parameters. Results of the analysis show that eliminating productivity variability, maintaining a reliable flow of resources, eliminating waste and simplifying the construction process are viable lean construction principles. On the other hand, eliminating output variability and reducing cycle time will not automatically lead to improved performance. Just as important, the research concludes that applying lean principles in construction is dependent on the construction hierarchy.