@inproceedings{Rathnayake2026_2514,
  author = {Rathnayake, Asitha and Murguia, Danny and Asmone, Ashan Senel and Middleton, Campbell},
  editor = {Hamzeh, Farook and Poshdar, Mani and Garcia-Lopez,, Nelly P. and Gan, Vincent},
  title = {Understanding performance limits in off-site structural frame construction},
  booktitle = {Proceedings of the 34th Annual Conference of the International Group for Lean Construction (IGLC 34)},
  year = {2026},
  pages = {775--786},
  address = {Singapore, Singapore},
  issn = {2789-0015},
  doi = {10.24928/2026/0212},
  url = {https://www.iglc.net/papers/details/2514},
  abstract = {Off-site construction is promoted as a means of improving productivity in the construction industry. Its standardised production processes create a favourable environment for applying lean principles. However, evidence suggests it does not always result in faster construction. We investigate the reasons by analysing the superstructure work package of a 14-storey residential building in London, using installation data for 2,070 precast columns, twin-wall cores, and lattice slab components. Construction speed, measured as the production rate (m² of floor area per day), showed a significant linear relationship with installation variability. Variability arose from factories producing similar components in batches for multiple projects, delays in issuing designs to factories, and out-of-sequence deliveries to sites with limited storage capacity. Handovers between off-site and on-site activities also exhibited greater variability than purely on-site handovers. The findings suggest that, if variability were minimised, construction speed would follow an inverse U-shaped trend, with initial improvements due to workers’ learning effects, followed by subsequent reductions associated with longer transportation distances for pre-manufactured components at higher levels. This study quantifies the variability-performance relationship in off-site construction and identifies the interface variability gradient between off-site and on-site handovers.},
  keywords = {Modular and off-site construction, productivity, variability, logistics, learning.},
}