Considered a modern method of construction, modular integrated construction (MiC) shifts construction work into factories wherein manufacturing knowledge developed since late 19th-century Taylorism can be possibly harnessed. While lean principles have been introduced to MiC, it is unclear whether prevailing MiC manufacturing is lean enough. Traditional means of evaluating leanness were widely criticized when they were introduced as “scientific management.” This research aims to assess the leanness of MiC manufacturing by adopting a scientific but non-intrusive method.
Firstly, the current manufacturing process is analyzed using value stream mapping to identify non-value-added activities and define the ideal leanness frontier as a benchmarking baseline. Then, a super-efficiency slack-based measure-data envelopment analysis model is developed to calculate a leanness score ranging from 0 to 1 at three nested levels: component (e.g. material cutting and 2D panel formation), module (e.g. 3D framework and finishing) and project.
Results from an in-depth case study in a MiC factory indicate leanness scores ranging from 0.05 to 0.68 for components and from 0.10 to 0.78 for modules. The overall leanness score of the focal project is around 0.3, revealing a MiC production process that is far from lean.
Introducing a method to non-intrusively quantify and monitor lean implementation, this research provides a structural approach to anatomize MiC manufacturing for continuous improvement. The proposed method can help researchers and practitioners to anatomize MiC manufacturing processes, examine their value-added and wasteful activities, benchmark them against an ideal frontier and identify areas for further improvement. The evaluation of the leanness in MiC manufacturing can facilitate the optimization of the production process, which further benefits the coordination with the supply chain and onsite installation through reduced waste and production delays, therefore serving as the basis of the lean application in the entire project.
