Abstract

Canada needs 3.5 million new homes by 2030 to address the ongoing housing affordability crisis. To meet this demand, offsite construction methods are viewed as a potential solution to increase housing supply. Among these methods, panelized construction is widely adopted because it offers benefits such as enhanced design flexibility and cost-effective assembly. However, it is more complex than other offsite construction methods, such as modular construction, as managing the production, transportation, and onsite assembly of individual panels is more demanding than delivering fully assembled modular units. Effective coordination among supply chain entities—including factory, trucks, trailers, and project sites—is therefore essential to mitigate operational conflicts that can lead to cost overruns and schedule delays. Yet, such coordination is hindered by the absence of an effective and systematic master planning and scheduling approach that integrates factory production, transportation, and onsite assembly. Current practices are manual and time-consuming, resulting in bottlenecks, underutilized resources, excess inventory, extended supply chain makespan, and increased costs.
This research presents a Just-in-Time-based integrated master planning and scheduling framework for supply chain management in panelized construction to synchronize factory production with transportation and onsite assembly. The framework comprises four key components: (1) a supply chain management structure framework that integrates supply chain operations and characterizes their relationships across planning and scheduling levels; (2) a supply chain master planning method that adopts Just-in-Time principles to align production with onsite needs, manages shared resources between sites, coordinates reverse transportation flow using a GIS map, and accounts for panel customization and practical planning rules; (3) an integrated master scheduling and resource allocation method consisting of factory production scheduling, logistics scheduling, and onsite assembly scheduling models; and (4) an automated and optimized scheduling system that integrates the developed planning and scheduling methods. The system comprises heuristic scheduling algorithms, a self-adaptive genetic algorithm–based multi-objective optimization algorithm, and a hybrid multiagent simulation to evaluate and optimize scheduling scenarios.
A prototype of the system is developed and validated through case studies from a panelized home prefabrication facility. Actual operational data are used to assess the effectiveness of the developed planning and scheduling methods and verify the system outputs. The results demonstrate that the developed methods coordinate supply chain operations to meet project delivery dates while managing shared resources under dynamic conditions. The system identifies optimal scheduling parameters, including project priorities and resource quantities, to improve supply chain performance in terms of makespan and cost. A master schedule generated without optimization reduces the supply chain makespan from 43 days in the actual schedule to 34 days, while optimization further reduces it to 29 days. Compared with the actual schedule, daily factory inventory decreases from the equivalent of 5 days of production capacity to approximately 1–2 days. Overall, this research advances the automation and optimization of supply chain master planning and scheduling in panelized construction by addressing coordination requirements for multi-line factories and incorporating practical transportation and onsite operational considerations across multiple projects.