Application of Lean Manufacturing Principles to Construction

RT-191 defined lean construction as: “the continuous process of eliminating waste, meeting or exceeding all customer requirements, focusing on the entire value stream, and pursuing perfection in the execution of a constructed project.” This research identifies the core principles of lean production, compares and contrasts the manufacturing and construction industries, and identifies the potential for implementing lean principles in the construction industry as well as a questionnaire for Self-Assessment of Lean Behavior.

Using lean concepts as a foundation, RT-191 first defined the nature of value-adding actions and waste. The research documents the definition of Value Adding (VA), Non Value Adding but Required (NVAR) and Non Value Adding (NVA) activities with case studies outlining the Value Stream for Structural Steel and Process Piping.

A significant finding was the large amount of waste activities (defined as anything that takes time, resources or space but does not add value to the product or service delivered to the customer) in construction as compared to manufacturing. The research determined that only 10 percent of field construction activities add value. If a contractor could improve the value-adding portion 5-20 percent, the lean contractor would have a significant competitive advantage.

RT-191 interviewed lean manufacturers, early adopters of lean construction methods, and academics and theorists from around the world. Using all of this information led to the identification of five lean construction principles that can significantly benefit both owners and contractors.

• Customer focus
• Culture and people
• Workplace organization and standardization
• Elimination of waste
• Continuous improvement and built-in quality

RT-191 found that lean behavior among construction contractors usually is confined to the first two principles. The remaining three principles are more difficult to implement, particularly because of the vast differences between the manufacturing and construction industries. Also, the use of those last three principles, even among contractors actively pursuing the lean ideal, is rare because to be truly lean requires changes to every aspect and every level of an organization. Regardless, construction’s processes can be improved, and applying lean principles should be considered. Becoming lean is a long-term, comprehensive commitment that requires a cultural change for the organization.