Off-site Construction Research Articles

Blockchain technology applicability in New Zealand’s prefabricated construction industry

Abstract Different industries are modernising their systems and introducing innovations to their management practices. However, the construction industry is recognised for its lack of technological systems on which the success of this sector is deemed to be heavily dependent. Previous studies have focused on enhancing the off-site construction supply chain. However, studies on the importance and utilisation of technology in this sub-sector are scarce, predominantly where the efficiency of off-site supply chain management is stalled as a consequence of the slow implementation of technology. Thus, this article employs an exploratory approach by providing insight into the applicability of blockchain technology in New Zealand’s off-site construction and demonstrates the benefits associated with the adoption of this technology. A literature review was used to identify stakeholders’ interrelationships in different stages of prefabrication projects. Then, a pilot interview from industry experts followed by a questionnaire survey was used to determine the involvement of stakeholders in different phases and the benefits that blockchain technology can bring to this industry. The results indicate that using blockchain as a secure information management system could improve the integration of prefabrication supply systems by producing a collaborative atmosphere amongst the organisations involved.

Off-Site Construction of Concrete Housing in the Andean Region: Advantages and Disadvantages

The construction of prefabricated houses is a viable option to solve the problems of housing demand in the Andean region. The prefabricated concrete houses have been built in several countries in the region and will surely be developed in the future. Thinking about their constructability, information is required about this construction system, which is scarcely known by the main people involved in construction: governments, users and builders. The present work seeks to fill the knowledge gap on the production and assembly of prefabricated concrete housing (PFCH), as well as on its advantages and disadvantages. For this purpose, a search for providers of this type of housing was carried out in Argentina, Bolivia, Colombia, Chile, Ecuador and Peru. Through an analysis of documentary information and interviews with the managers of the supplier companies, it was established that one of the main aspects in this construction system is the definition of the constituent elements of the house as this defines the need for equipment and hand of work for its assembly. The main advantage is the short execution time, while among the disadvantages is the poor adaptability of the designs. There are conflicting opinions as to whether its cost is an advantage. This research contributes to the constructability of PFCH in the Andean region, facilitating knowledge that can be integrated in the design and in the construction stage in order to improve the performance of the construction process.

Nomenclature for offsite construction

ABSTRACT The global rise of offsite construction has created a compelling need for more efficient information management. This paper reports the development of a nomenclature system for components to enable better information management in offsite construction projects in the digital era. Firstly, criteria for suitable names are derived from current construction practices, other matured naming practices and information quality requirements. Then, through collaboration with industrial stakeholders to balance different needs and arrive at common understandings, we propose a nomenclature system that confers names upon offsite construction components. The system is validated and refined through a project-level case study and a policy-level focus meeting. The key contributions of this study are to articulate the widespread but rarely explored need for a nomenclature system for offsite construction, to exhibit the criteria for such a system and to describe the process of development with collaboration of the industry. Future research is encouraged to investigate the optimal component level for a name, develop automatic naming tools, and modify and validate the nomenclature system in other regions.

Prefabrication supply chains with multiple shops: Optimization for job allocation

Prefabrication or off-site construction is a growing trend contributing to productivity improvements. It motivates specialty contractors and suppliers to operate multiple fabrication shops close to market regions, where a shop can produce and delivery prefabricated components in a timely fashion and at a minimal cost. Few quantitative models are available to assist companies with scheduling and allocation questions. This research utilizes optimization to answer these questions supporting the production planning in prefabrication supply chains. The paper presents an optimization model that seeks minimal cost while considering job demands and shop capacities. Computational results suggest that the model generates a lower-cost production schedule than the early due date (EDD) method. It also indicates that varying due dates cause changes in total cost. Moreover, this research supports decision-makers by analyzing the impacts of changing shop capacities regarding available machines. It provides further insight into construction supply chain management with multiple shops.

Vision-based method for tracking workers by integrating deep learning instance segmentation in off-site construction

Vision-based tracking of construction workers is the fundamental step for many automated applications in off-site construction. This research proposes a vision-based method for tracking workers in off-site construction by integrating deep learning instance segmentation. The proposed method consists of three main modules including instance segmentation, instance association, and instance assignment. The instance segmentation module applies the Mask R-CNN algorithm to extract masks and bounding boxes of workers from videos. Then, an association matrix is constructed at each two consecutive frames based on the mask intersection-over-union and Kalman filtering. Finally, the instance assignment module solves the association matrix to produce tracking results. In experiments, the proposed method achieved the multiple object tracking accuracy of 96.4% and multiple object tracking precision of 86.2%. The testing results indicate the developed method can successfully track multiple workers when facing the challenges of occlusions and scale variations, etc.

Structural equation modeling of the critical driving forces of offsite construction in Ghana

PurposeThe construction sector suffers significant challenges which are intertwined with processes and products of the traditional onsite construction approach. The quest for a lasting solution to these problems is heralding the change toward offsite construction. Amid the scaling drive, to date there are no official reports and contribution to knowledge on the drivers of offsite construction in Ghana. This study models the structural paths of the critical drivers of offsite construction in Ghana.Design/methodology/approachData were collected through a questionnaire from 95 respondents in the Ghanaian construction industry. Exploratory factor analysis and Partial least squares structural equation modeling were employed to analyze the data.FindingsThe results revealed that industry dynamics are the governing drivers of offsite construction in Ghana. As such, factors such as the rocketing housing deficits, high cost of acquiring land permanently, high cost of cast-in-situ construction, the utilization of prefabricated shipping containers for construction and construction market demand constitute the governing drivers of offsite construction in Ghana. Similarly, concern for higher productivity is a critical driver of offsite construction in the Ghanaian construction industry. On the contrary, findings show that performance-related drivers, government policy and regulation, and technological innovation exert little influence in driving offsite construction in Ghana.Practical implicationsThe appreciation of the drivers may help stakeholders to understand the important mechanisms underlying offsite construction in Ghana, and thereafter help them to make more informed decisions regarding its implementation.Originality/valueThe findings contribute some interesting dimensions to the global debate on offsite construction by discovering and adding two drivers of offsite construction peculiar to developing countries (high cost of acquiring land permanently, and the utilization of shipping containers for construction) to the literature.

Explaining the Formation Mechanism of Intrateam Knowledge Exchange Network in Offsite Construction Projects: A Social Cognitive Perspective

AbstractIssues related to effective knowledge sharing and diffusion are pressing and have emerged in the field of offsite construction. Significant research on project-based organization knowledge ...

The Role of Building Information Modeling in Offsite Construction Projects

Offsite construction (OSC) and building information modeling (BIM) are two new and promising developments in the construction industry. However, few studies to date provide general empirical evidence for the role of BIM in OSC projects. Based on a comprehensive literature review, this research performs an investigation in the UK construction industry into OSC in the context of BIM with a large and representative sample of empirical data. The analysis of empirical data demonstrates that working with BIM makes OSC easier and more effective. With regards to the integration of OSC and BIM, there are no significant differences in attitudes between project parties. It is found in this research that BIM plays various important roles in OSC design, manufacturing, transportation and construction, which significantly contribute to OSC project success. This research presents a model to conceptualize BIM-driven OSC. It also identifies the need for further transforming from BIM-driven OSC to more advanced digital-driven OSC through the integration of OSC and multiple digital technologies.

Off-Site Construction Three-Echelon Supply Chain Management with Stochastic Constraints: A Modelling Approach

Off-site construction is becoming more popular as more companies recognise the benefits of shifting the construction process away from the construction site and into a controlled manufacturing environment. However, challenges associated with the component supply chain have not been fully addressed. As a result, this study proposes a model for three-echelon supply chain supply management in off-site construction with stochastic constraints. In this paper, multiple off-site factories produce various types of components and ship them to supplier warehouses to meet the needs of the construction sites. Each construction site is directly served by a supplier warehouse. The service level for each supplier warehouse is assumed to be different based on regional conditions. Because of the unpredictable nature of construction projects, demand at each construction site is stochastic, so each supplier warehouse should stock a certain number of components. The inventory control policy is reviewed regularly and is in (R, s, S) form. Two objectives are considered: minimising total cost while achieving the desired delivery time for construction sites due to their demands and balancing driver workloads during the routeing stage. A grasshopper optimisation algorithm (GOA) and an exact method are used to solve this NP-hard problem. The findings of this study contribute new theoretical and practical insights to a growing body of knowledge about supply chain management strategies in off-site construction and have implications for project planners and suppliers, policymakers, and managers, particularly in companies where an unplanned supply chain exacerbates project delays and overrun costs.

Additive Manufacturing in Off-Site Construction: Review and Future Directions.

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.

Reinforcement learning approach to scheduling of precast concrete production

The production scheduling of precast concrete (PC) is essential for successfully completing PC construction projects. The dispatching rules, widely used in practice, have the limitation that the best rule differs according to the shop conditions. In addition, mathematical programming and the metaheuristic approach, which would improve performance, entail more computational time with increasing problem size, let alone its models being revised as the problem size changes. This study proposes a PC production scheduling model based on a reinforcement learning approach, which has the advantages of a general capacity to solve various problem conditions with fast computation time and good performance in real-time. The experimental study shows that the proposed model outperformed other methods by 4–12% of the total tardiness and showed an average winning rate of 77.0%. The proposed model could contribute to the successful completion of off-site construction projects by supporting the stable progress of PC construction.

A Systematic Review on Supply Chain Management in Prefabricated House-Building Research

Prefabricated house-building companies, as suppliers or supply chains, which use manufacturing as a business approach towards industrialization, struggle to implement principles and optimal practices driven from well-established and validated theories in operational research. Supply chain management has a mature body of knowledge that has been widely adopted by research on offsite construction to improve its performance at an organisational level. However, there is no comprehensive review available in the literature for supply chain management theory within prefabricated house building research from the perspective of suppliers. In this study, a systematic review was conducted on the available literature on supply chain management within prefabricated house-building research. Initially, qualitative analysis was performed to identify the key themes. Later, quantitative analyses were applied to validate the overlapping themes and keywords. Further, key trends related to focus, methods and theories or frameworks were reported. The findings were discussed in the context of recent developments in all principal component bodies of supply chain management for future work. This study also provides a brief guide for potential future review studies to explore interdisciplinary intervention within the offsite stream.

Structural response of reinforced concrete volumetric building in low seismicity regions

Recent advancement in offsite volumetric construction shows that volumetric buildings (VB) are getting popular among the prefabrication industry. Although volumetric construction has been used to build numerous tall buildings in Singapore and Australia, its structural behavior is not thoroughly researched and published in the literature. Hence, this paper examines the structural response of centric reinforced concrete VBs of 10-story and 25-story through a performance-based design framework using finite element modelling. These VBs are first designed elastically under wind actions, then subject to incremental secant stiffness response spectrum analysis for seismic actions. The Eurocode 8 Malaysian National Annex is used to simulate various ground types according to site natural period. The base shear contribution of RC module to the lateral force-resisting system of VB was found to be significant, and a high ratio of seismic-to-wind demand was expected for VB situated in the low-seismicity region such as Malaysia.

A cyber-physical system approach to zero-defect manufacturing in light-gauge steel frame assemblies

Recent advances in manufacturing research have set the stage for the industrial integration of zero-defect manufacturing strategies, aiming towards a more sustainable production paradigm. A systematically deployment guideline to implement zero-defect manufacturing is needed to transform the future cyber-physical factory floor. This paper describes a novel framework based on a well-known cyber-physical architecture that provides advanced information analytics, robust information flows, and data acquisition systems that support defect detection and prediction introduces repair technologies and sets up procedures for preventive maintenance. Through continuous inspection of product and equipment status during the manufacturing process, raw quality and tool health data from different sources is used to obtain key performance indicators. Statistical tools such as cross-correlation are then applied to quantify underlying relationships between product quality specifications and equipment health. The resulting correlations are then used to reduce non-conformance of products manufactured by implementation of preventive maintenance. A unified implementation for zero-defect manufacturing cyber-physical processes eases their integration in future Industry 4.0 facilities and validated in the context of offsite construction manufacturing of steel frame assemblies.

Development of an Offsite Construction Typology: A Delphi Study

Offsite construction (OSC) delivers multiple products that vary in design and building complexity. Considering the growing prevalence of OSC, a systematic categorization of OSC types can offer operational and macroeconomic benefits to the construction industry. The purpose of this study is to develop an OSC typology through a systematic process, as existing studies do not present a rigorously evaluated typology that suits the modern OSC context. The research addresses the following research question: what are the distinct characteristics of unique OSC types that have emerged through the adoption of Industry 4.0-based technological advancements? Due to the rapid advancement of production and construction technologies, the existing OSC classifications are becoming outdated. As such, a detailed review of OSC technologies was conducted which enabled the identification of OSC categories: components, panels, pods, modules, complete buildings, and flat-pack (foldable structure). A series of case studies was then reviewed to explore and analyze the relevance of these OSC types in practice. It was then subjected to a Delphi-based multi-level expert forum to develop a modern and future-proof OSC typology. The rigorous process validated, defined, and delineated the boundaries between the OSC types. The research confirmed that OSC types can be broadly categorized as volumetric (pods, modules, complete buildings) and non-volumetric (components, panels, foldable structure). The results indicated that OSC skills vary with the complexity of OSC types, and that lightweight steel and timber are the most common materials.

Seismic performance of modular steel buildings (MSBs) equipped with resilient slip friction joints (RSFJs)

Modular construction is becoming a prevalent technique combining off-site construction and on-site assembly to provide fast, reliable and high-quality permanent buildings. The modular method is a good alternative to traditional on-site construction when the layout consists of repetitive units such as hotels and multifamily dwellings, and when the construction schedule is tight. The dynamic performance of Modular Steel Buildings (MSBs) has not yet been fully studied, and a limited number of investigations on the nonlinear dynamic behavior of MSBs showed that they are susceptible to damage during strong ground motions. This paper considers the use of a self-centering energy dissipation device, called Resilient Slip Friction Joint (RSFJ), in MSBs to avoid seismic damage, enable immediate occupancy, and reduce the repair costs after a severe earthquake event. Two different configurations of RSFJs (namely tension-compression and tension-only configurations) were introduced to Seismic Force Resisting Systems (SFRSs) of 6- and 12-story MSBs. This study presents a step-by-step design procedure by following the capacity design for RSFJs in accordance to National Building Code of Canada (NBCC). The dynamic performances of both configurations were evaluated by performing bi-directional Nonlinear Time History Analysis (NLTHA). In addition to global response of MSBs, component level maximum demands of RSFJs were assessed to shed a light on the overall performance of MSBs under three different hazard levels. It was shown that low- and mid-rise MSBs can efficiently be equipped with RSFJ to mitigate earthquake-induced vibrations and minimize the damage to the structural members.

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

Off-site construction is a modern construction method that brings many sustainability merits to the built environment. However, the sub-optimal planning decisions (e.g., resource allocation, logistics and overtime planning decisions) of off-site construction projects can easily wipe away their sustainability merits. Therefore, simulation modelling—an efficient tool to consider the complexity and uncertainty of these projects—is integrated with metaheuristics, developing a simulation-optimization model to find the best possible planning decisions. Recent swarm intelligence metaheuristics have been used to solve various complex optimization problems. However, their potential for solving the simulation-optimization problems of construction projects has not been investigated. This research contributes by investigating the status-quo of simulation-optimization models in the construction field and comparing the performance of five recent swarm intelligence metaheuristics to solve the stochastic time–cost trade-off problem with the aid of parallel computing and a variance reduction technique to reduce the computation time. These five metaheuristics include the firefly algorithm, grey wolf optimization, the whale optimization algorithm, the salp swarm algorithm, and one improved version of the well-known bat algorithm. The literature analysis of the simulation-optimization models in the construction field shows that: (1) discrete-event simulation is the most-used simulation method in these models, (2) most studies applied genetic algorithms, and (3) very few studies used computation time reduction techniques, although the simulation-optimization models are computationally expensive. The five selected swarm intelligence metaheuristics were applied to a case study of a bridge deck construction project using the off-site construction method. The results further show that grey wolf optimization and the improved bat algorithm are superior to the firefly, whale optimization, and salp swarm algorithms in terms of the obtained solutions’ quality and convergence behaviour. Finally, the use of parallel computing and a variance reduction technique reduces the average computation time of the simulation-optimization models by about 87.0%. This study is a step towards the optimum planning of off-site construction projects in order to maintain their sustainability advantages.

Blockchain and Information Integration: Applications in New Zealand’s Prefabrication Supply Chain

New Zealand’s rising demand for new and affordable homes is driving innovative and effective methods for project delivery. Prefabrication or off-site construction is considered an innovative approach to project delivery that eliminates the limitations of traditional construction methods. However, the prefabrication industry struggles with several challenges, including poor coordination and low supply chain integration amongst its partner organisations. There has been previous literature on improving the prefabrication supply chain integration, but few studies about the role of technology in this sector. Therefore, this article provides intuitions into the applicability and benefits of advanced technologies, namely blockchain, for improving supply chain integration in the context of prefabrication in New Zealand. A questionnaire survey was used to identify the channels used for information exchange between clients and contractors. Moreover, the questionnaire ascertained the positive effects of blockchain on enhancing supply chain integration between the two partners. Blockchain has proven to be a secure information integration instrument that can improve the integration of the prefabrication supply chain by fostering collaboration between organisations.

High-Resolution Direct Push Sensing in Wetland Geoarchaeology—First Traces of Off-Site Construction Activities at the Fossa Carolina

Wetland environments, with their excellent conservation conditions, provide geoarchaeological archives of past human activities. However, the subsurface soil is difficult to access due to high groundwater tables, unstable sediments, and the high cost of excavation. In this study, we present a ground-based non- and minimal-invasive prospection concept adapted to the conditions of wetlands. We investigated the Fossa Carolina in South Germany, a canal that was intended in 792/793 AD by Charlemagne to bridge the Central European Watershed. Although the resulting Carolingian banks and the fairway with wooden revetments are very imposing, archaeological traces of off-site construction activities have not been identified hitherto. Based on a geophysically surveyed intensive linear magnetic anomaly parallel to the Carolingian canal, we aimed to prove potential off-site traces of Carolingian construction activities. In this context, we built up a high-resolution cross-section using highly depth-accurate direct push sensing and ground-truthing. Our results showed the exact geometry of the canal and the former banks. Thus, the magnetic mass anomaly could be clearly located between the buried organic-rich topsoil and the Carolingian banks. The thermoluminescence dating showed that the position of the magnetic mass anomaly reflected Carolingian activities during the construction phases, specifically due to heat exposure. Moreover, we found hints of the groundwater supply to the 5-metre wide navigable fairway.

Investigating digital technological competencies amongst black Asian minority ethnic construction students in the UK

PurposeThis study aims to investigate digital technology (DT) competencies, training and awareness amongst Black Asian Minority Ethnic (BAME) construction students in the UK.Design/methodology/approachThis study uses a quantitative online survey to investigate both BAME Construction Undergraduates Graduate Students (CUGS) and staff studying on and teaching on Construction programmes. The investigation examined their opinions as to their own awareness of their competencies and training regarding DT.FindingsFindings indicate that BAME CUGS were mostly “very proficient” in the use of basic DT, such as required to complete an authentic assessment that typifies a real-life scenario. For example, sending and receiving emails, Excel, Word, computer literacy/basic IT skills, browsing searching materials, PowerPoint, specialist IT skills, mobile devices, tablet and social media handles. However, findings revealed that training awareness and competencies in new DT is shallow, and BAME CUGS are probably not ready for the digitalised construction world. Respondents were mainly within the “probably aware” range, and very few were within the “definitely aware” range, on the Likert scale adopted. New DTs that fell within the “definitely aware” range are BIM, offsite construction and manufacturing, 3D printing, cloud computing and collaboration.Research limitations/implicationsIt is acknowledged that expanding the sample size to other universities and exploring BAME industry professionals’ narratives could further enrich the discussion. However, these limitations did not impact the robust practical and theoretical implications provided to CUGS, Higher Education (HE)sectors, University staff and industry emerging from the analysis and findings achieved in the study. Still, it is being recommended for future work to consider.Originality/valueThe study provides valuable recommendations helpful to HE institutions, industry and government. Recommendations provided include a need to review and update the current curriculum, robust partnership between academia and industry, increase government funding, upskilling and training staff in the new DT.