Optimization of Prefabricated Components in Housing Modular Construction

Abstract

In modular construction—a type of industrialized construction—production planning is very important, as it is closely related to the project’s duration, quality, and sustainability. The constraints (production area, delivery due date) often differ for each project, yet production planning in modular construction has failed to change with the project characteristics. As a result, bottlenecks and construction delays are common problems seen in modular construction, which, in turn, decreases the production ratio, causing the production to be inefficient. To this end, this paper applied a prefabricated component in the modular production process. The paper developed a process analysis model considering constraint factors (production period, production area) to derive the optimal configuration of the prefabricated components in various alternatives. The developed analysis model was then applied to a virtual case to analyze the productivity improvement and select the optimal process. The optimal production process was derived by simulating the possible production planning within a limited production area and production timeline. The result of a simulation indicates that the production period has been halved by optimizing the process. Furthermore, by applying prefabricated components, the production efficiency was further increased because the existing linear production process’s bottleneck disappeared. The model is deemed to have the potential to optimize various production methods across production facilities or modular factories that simultaneously perform multiple projects.

Simulation-Optimization for the Planning of Off-Site Construction Projects: A Comparative Study of Recent Swarm Intelligence Metaheuristics

“…(2) SO with metaheuristics requires the call of the simulation model frequently to evaluate the fitness of each individual solution of the population in each iteration. (3) Finding the optimum values of the controllable parameters for each metaheuristic requires extensive numerical experiments. (4) Construction researchers tend to hybridize DES with other simulation approaches such as system dynamics [46] or integrate it with neural networks [47].…”

“…Regarding the project's cost (TPC), Equation (3) shows that it equals the sum of the direct (DC) and indirect costs (IC). Equation (4) shows that the indirect costs include the overheads (CIC) and the mobilization and demobilization costs (MC) of each piece of equipment and human resource used in the production, logistics and installation processes.…”

“…Off-site construction (OSC) is a sustainable construction method in which parts of the structure are produced off-site and then transported to the construction site for erection [1,2]. OSC has many advantages for the improvement of productivity [3], quality [4], and safety [5] of the built environment. Besides this, OSC brings environmental improvements to the construction industry [6].…”

“…These complex interactions form queues inside the system, making the analytical methods impractical for the modelling of such queuing systems [23]. (3) the previous models assumed that the activities' durations and costs are deterministic without considering the uncertainty associated with these types of projects [24].…”

Exploring Key Factors for Contractors in Opening Prefabrication Factories: A Chinese Case Study

“…Bottlenecks and construction delays are common problems due to inefficient construction site production. Prefabricated components can reduce bottlenecks, improve production rates, and shorten production times (6). In addition, weather does not have significant negative impacts on prefabricated construction assembly and this effectively ensures construction efficiency (7).…”