Modular construction brings improved safety and mitigates risks of hazard and injury. However, modular construction technology is also challenged with a degree of uncertainty resulting from such internal and external factors as engineering, occupational, cultural, socio-economic, and financial. Since modular construction is by nature distinct from conventional construction, existing risk management research for onsite construction cannot be directly applied to modular construction. This paper describes research on the risk management associated with modular construction, focusing on: (1) identifying risk factors and (2) assessing the impacts of the identified risk factors on project cost and duration. The primary risk factors associated with modular construction are identified, and fuzzy analytic hierarchy process (AHP) is utilized to rank these factors; simulation techniques are employed to assess the risks of projects. The risk identification and ranking are evaluated by a focus group of experts from the modular construction industry; t-distribution and chi-squared distribution are applied to analyze the results. The case of a project in Edmonton, Canada is presented to illustrate application of the proposed methodology.

Additive manufacturing (AM) is one of the pillars of Industry 4.0 to attain a circular economy. The process involves a layer-by-layer deposition of material from a computer-aided-design (CAD) model to form complex shapes. Fast prototyping and waste minimization are the main benefits of employing such a technique. AM technology is presently revolutionizing various industries such as electronics, biomedical, defense, and aerospace. Such technology can be complemented with standardized frameworks to attract industrial acceptance, such as in the construction industry. Off-site construction has the potential to improve construction efficiency by adopting AM. In this paper, the types of additive manufacturing processes were reviewed, with emphasis on applications in off-site construction. This information was complemented with a discussion on the types and mechanical properties of materials that can be produced using AM techniques, particularly metallic components. Strategies to assess cost and material considerations such as Production line Breakdown Structure (PBS) and Value Stream Mapping are highlighted. In addition, a comprehensive approach that evaluates the entire life cycle of the component was suggested when comparing AM techniques and conventional manufacturing options.

Off-site construction is an innovative type of construction with the philosophy of standardizing the process and deploying the latest technological enablers. Many technologies, such as the Building Information Model (BIM), Internet of Things (IoT), etc., are concerned with virtual representation and manipulation of the physical site. However, a holistic view of the off-site construction processes is lacking in the exploration of the technological advances, resulting in inconsistency when applying these advances in practice. The concept of Digital Twin is useful for addressing this challenge. Digital Twin is a philosophy and a collection of technologies aimed toward seamless physical and virtual connections. Therefore, a holistic Off-site Construction Digital Twin model is necessary for any research concerning this topic, and an assessment framework is useful in helping off-site construction industry companies in approaching systematic Digital Twin. This research first proposes a model for Off-site Construction Digital Twin. To quantify this model, an assessment tool named Off-site Construction Digital Twin Maturity Level is proposed. The validation and evaluation of this assessment framework are conducted through a case study with ACQBuilt, an off-site construction company in Edmonton, Canada. The resulting assessment framework contributes to the body of knowledge in two ways: Firstly, it sets the foundation for an Off-site Construction Digital Twin, which is anticipated to significantly reduce waste and to improve efficiency. Secondly, it enables easier technology application in practice by offering a holistic Digital Twin framework.

Due to its similarity to industrialized products, the offsite construction industry is seen as a focus for the transformation of Construction 4.0. Many digital technologies have been applied or have the potential to be applied to realize the integration of design, manufacturing, and assembly. The main objective of this review was to identify the current stage of applying digital technologies in offsite construction. In this review, 171 related papers from the last 10 years (i.e., 2013–2022) were obtained by collecting and filtering them. They were classified and analyzed according to the digital twin concept, application areas, and specific application directions. The results indicated that there are apparent differences in the utilization and development level of different technologies in different years. Meanwhile, the introduction, current stages, and benefits of different digital technologies are also discussed. Finally, this review summarizes the current popular fields and speculates on future research directions by analyzing article publication trends, which sheds light on future research.

At present, industrial projects are constructed primarily using a prefabricated approach. The modules are produced in an off-site facility and transported on transport trailers to the construction site where they are lifted by mobile cranes. One of the keys to the success of modular industrial projects is efficient crane planning, which includes path checking to find whether or not a crane has a feasible path through which to lift a module over obstructions in a congested plant. However, due to the large number of lifts, the manual path-checking practice is quite tedious and prone to error. In light of this problem, this paper proposes a methodology for automatically checking the lift paths for industrial projects. The proposed methodology simplifies and represents the three-dimensional site layout using project elevations. For each elevation, the crane feasible operation range (CFOR) is calculated based on the crane’s capacity and clearances, as well as site constraints. The pick area (PA) is cal...