Lean-mod: An approach to modular construction manufacturing production efficiency improvement

Modular construction manufacturing (MCM) is superior to the current on-site construction system which is hampered by inefficiency and material and process waste. Modular buildings are potentially built through a more efficient and cost-effective method, but in the current manufacturing-based approach, a gap still exists between design and production. The increased interest in modular buildings demands special methods of design and manufacturing to support effective production operation. MCM provides opportunity to apply Lean for production efficiency in the plant. Lean is a concept first developed in the manufacturing industry which has been since adapted to the construction industry. Although the focus of Lean in both industries is the same, Lean principles vary between manufacturing and construction since these two industries differ in nature. Lean as the concept is applicable to any industries, taking into consideration that MCM has characteristics of both manufacturing and construction yet is distinct and should be seen in the class of its own. Given the distinct nature of MCM, the technical elements in “Lean production” and “Lean construction” are not sufficient to achieve the Lean goals for MCM industry, necessitating a modified framework by which to exploit the potential benefits of modular building. The focus of this research is to develop a framework that supports manufacturers’ needs for design and which encompasses the integration of Lean into production process. In this research, Lean is adopted for the MCM industry in order to improve production process efficiency which is introduced as “Lean-Mod”. To apply the proposed Lean-Mod strategies on a factory production line, an enhanced integrated approach of Building Information Modeling (BIM), Lean, and simulation is proposed. Integrating these concepts involves transferring generated data from a BIM model to the manufacturing phase, where Lean strategies are applied, and evaluating the production process scenarios through simulation modeling. The simulation model of production flow evaluates improvement from the Lean point of view and provides assessment of potential scenarios. The proposed methodology is validated by a case study—a residential modular factory located in Edmonton, Canada—and illustrates the effectiveness of the proposed methodology.