Construction and demolition waste - a shift toward Lean Construction and Building Information Model

Waste in the construction industry is a devastating dilemma, especially that construction and demolition activities are considered as the highest waste generator globally. Countries have developed regulations: policy-makers and professional associations have provided norms and policies to manage C&D waste. Previous studies, however, have revealed insufficiencies in the current regulations and norms in incentivizing the industry practices toward waste prevention, since its culture is characterized by the gap in technological use, insufficient knowledge, poor planning, and poor information flow. This research provides a literature review on the current research findings and trends in managing C&D waste. Then based on design theory and theory of production, an exploratory research consisting of BIM and Lean construction concepts is provided. Lean can maximize the value of construction by addressing waste within portfolios, projects, and operations; BIM offers an enhanced collaborative platform with improved design practice and information management throughout buildings’ life cycle. The proposed conceptual framework enables economic, environmental, and social benefits to allow practitioners collaborate, analyze, and minimize construction waste throughout buildings’ life cycle.(undefined

Visual tool for workload leveling using the work density method for takt planning

This paper presents a novel interactive Visual Management tool, called ViWoLZo (Visual Workload Leveling and Zoning), that supports takt planning. It is based on the concept of “work density” to depict workloads visually as well as quantitatively so that it can be used to find an optimal workload level and associated work space zoning. ViWoLZo was created in the course of action research on two projects in the San Francisco Bay Area. Because the concept of work density is generic, the tool can be configured to any construction floor plan and process sequence pertaining to any phase of construction—involving repetitive or non-repetitive work—to help level the workload based on the selection of zones. In turn, this leveling informs the user’s selection of the takt to use in planning the work. This Visual Management tool delivers proof-of-concept that work density is useful in studying workload leveling and zoning alternatives for takt planning. Use of ViWoLZo replaces subjective approaches for deciding how to divide work space into zones. While work density data is not yet readily available, the tool illustrates what value such data can have by supporting a user’s what-if analyses to decide if the desired takt can be met, considering different production rates, preferences for zoning of work space, and other work structuring considerations. The paper concludes with suggestions for follow-on research, including recommendations for tool enhancements and integration of additional planning steps

Discussion of “Improving labor flow reliability for better productivity as lean construction principle” by H. Randolph Thomas, Michael J. Horman, R. Edward Minchin Jr., and Dong Chen

Thomas et al.’s paper has the stated objective, “…to test whether improving flow reliability improves construction productivity.” They understand flow in terms of both the flow of work, that on which resources are to be expended, and of labor. Improving flow reliability is said to be a lean construction principle, and it is concluded to be valid. However, they argue that advocates of lean construction have overemphasized work flow and underemphasized labor flow as a means for improving labor productivity. They present case studies to show that failures to manage flows substantially reduce labor productivity. A 51% loss of efficiency is attributed to flow management failures; 58% of those losses are attributed to failures in labor flow management and 42% to failures in work flow management. We reject the authors’ conclusion, as it misunderstands the problem to be solved, rests on a faulty argument that mischaracterizes the approach it criticizes, and proposes a solution that compounds the problem