摘要 :
Offsite passenger service facilities transfer passengers from a common location to an airport and may provide additional services such as baggage handling and passenger check-in. Although they are conceptually promising, there is ...
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Offsite passenger service facilities transfer passengers from a common location to an airport and may provide additional services such as baggage handling and passenger check-in. Although they are conceptually promising, there is a lack of modern methods specifically tailored to forecast their demand. This paper reports on the development of two sequential models that forecast demand for an offsite facility. Models were calibrated based on data collected at six airports in California, Maryland, Massachusetts, and Virginia. The results showed that likely candidates for an offsite facility are airports that are not easily accessible, and departing air passengers with early morning flight departure times and high variability in ground travel times to the airport. A case study demonstrates the application of the models to Virginia's Richmond International Airport.
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Purpose - This paper aims to examine the potentials of using automated guided vehicle (AGV) technology in modular integrated construction (MiC) to realise logistics automation in module manufacturing and transport. Design/methodol...
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Purpose - This paper aims to examine the potentials of using automated guided vehicle (AGV) technology in modular integrated construction (MiC) to realise logistics automation in module manufacturing and transport. Design/methodology/approach - This paper adopts a scenario approach through three phases (i.e. scenario preparation, development and transfer), with six steps performed iteratively. The scenarios were systematically developed using a six-aspect socio-technical framework. Data were collected through a comprehensive literature review, site visits and interviews with relevant stakeholders and professionals. Implications regarding strength, weakness, opportunities and challenges and future research directions are provided. Findings - The developed scenarios of "smart manufacturing" and "last-mile delivery" demonstrated how AGVs could be used to enhance efficiency and productivity in module manufacturing and transport The synergies between AGVs and emerging information technologies should pave a good foundation for realising logistics automation in MiC. Future research should address: how to define the tasks of AGVs, how will the use of AGVs impact MiC practices, how to design AGV-integrated module manufacturing/transport systems and how to integrate people factors into the use of AGVs in MiC. Practical implications - This paper reveals the socio-technical benefits and challenges of using AGVs in MiC. Originality/value - This study extends the understanding of using logistics automation in MiC as emerging research directions, with the intention of directing scholars' and practitioners' interest into future exploration. It is the first attempt in its kind. Its findings could be extended to constitute a comprehensive development roadmap and prospects of automation in modular construction.
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This study examines the current use of offsite construction techniques in the building sector of the U.S. construction industry, discusses the perceptions of experienced industry practitioners regarding the benefits and barriers o...
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This study examines the current use of offsite construction techniques in the building sector of the U.S. construction industry, discusses the perceptions of experienced industry practitioners regarding the benefits and barriers of using these techniques, and also identifies the top three reasons and challenges of using offsite construction techniques. The findings indicate that offsite construction techniques have not been widely used in the U.S. construction industry in 2005. The benefits of using offsite construction techniques include: 1) reducing project schedules, 2) reducing the need for skilled craft workers, 3) reducing the negative environmental impacts of construction operations, and 4) increasing the safety performance onsite. The lop three reasons for using these techniques were identified as reducing: 1) the construction duration, 2) overall project schedule, and 3) the effect of incremental weather conditions. The top three challenges of using these techniques were: I) inability to make changes in the field, 2) transportation constraints, and 3) limited design options. This study also discovers a strong, positive linear relationship between the architects/engineers' satisfaction level with offsite preassembly with the percentage of its use.
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Abstract Many researchers, as well as industry practitioners, believe that offsite construction methods are associated with a lower level of worker safety risks than traditional onsite construction methods. This study aims to test...
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Abstract Many researchers, as well as industry practitioners, believe that offsite construction methods are associated with a lower level of worker safety risks than traditional onsite construction methods. This study aims to test such belief by comparing the list of worker safety risks identified by site supervisors for both onsite and offsite construction scenarios for the same building components. Specifically, Safe Work Method Statements (SWMS)—prejob hazard assessments required by law in Australia—were collected from two projects where offsite manufacturing has been used, and they were used as a basis for the investigation. Additionally, interviews were conducted with the site supervisors who developed the Statements for a more in-depth investigation of the worker safety risks involved with onsite and offsite construction methods, respectively. The analysis reveals that the total risk score (the higher the score, the more numerous the safety risks) would decrease in the offsite construction scenarios in each case, mainly due to significantly fewer work-at-height tasks included in the offsite construction scenarios. This study contributes to the body of knowledge by providing an empirical, evidence-based explanation for why offsite construction can help reduce safety risks on construction sites.
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摘要 :
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 benefit...
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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.
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Offsite construction has been considered by academics and practitioners in many countries as an efficient way of delivering buildings. The benefits concerning time, cost and quality are well-documented. Even though the use of this...
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Offsite construction has been considered by academics and practitioners in many countries as an efficient way of delivering buildings. The benefits concerning time, cost and quality are well-documented. Even though the use of this technique provides many significant advantages, the current level of using these techniques in the French construction industry is limited. In addition, research studies that investigate this topic in France are rare. For these reasons, this study aims to fill the gap by first, explore the definition of construction industrialization in the French construction context and second, investigate the perceived benefits and hindrances of prefabrication’s applications. A questionnaire survey was conducted in order to target the main construction industry players: manufacturers, contractors, designers and consultants. More than 55 questionnaires were completed and returned. The results indicated that advantages of using these techniques include improving productivity, minimizing construction time, improving quality, reducing waste and openness to industrialization and automation of construction. The top four hindrances were requirement of a long coordination work between the design office and the pre-manufacturer before starting production, inability to block the design early enough to start production at the factory, key decisions already taken exclude the prefabrication approach and the obligation to accept the lowest cost.
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摘要 :
Offsite construction (OSC) transfers onsite construction activities to factory-based processes utilising technological advancements, resulting in new and emerging skills while causing some existing skills to be changed and others ...
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Offsite construction (OSC) transfers onsite construction activities to factory-based processes utilising technological advancements, resulting in new and emerging skills while causing some existing skills to be changed and others to be redundant. However, there are no established methods to systematically quantify these OSC skill requirements. This paper presents OSC skill prediction models while highlighting the process of model development for future research. The aim of these models is to predict skills using a comparable measure, manhours/m2. A skill classification with six skill categories was used to analyse OSC skills. Numerical model development methods were reviewed, and mixed-effect regression modelling was selected for model development. The skills data needed for regression modelling was collected using eight case studies. Predominantly panelised and modular OSC projects were used to collect skills data. The skill prediction models were validated using further case study data and an expert forum. Comparatively, modules OSC type requires higher skill quantities than panels, for all the six skill categories analysed. Onsite and offsite skill requirements vary for different OSC types. Additionally, complex, non-linear relationships were recognised between OSC types and the utilisation of their skills. This research presents unique OSC skill prediction models that can provide early-stage advice to policymakers, project planners and manufacturers on OSC skill requirements. It also provides a novel methodology to develop predictive models for specific industry scenarios that have non-linear and complex relationships.
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The construction sector and concomitant supply chain has been acknowledged in the literature as a major contributor to environmental “stress”, from the design, sourcing and extraction of raw materials through to transportation, ...
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The construction sector and concomitant supply chain has been acknowledged in the literature as a major contributor to environmental “stress”, from the design, sourcing and extraction of raw materials through to transportation, design, construction and demolition. Clear indicators/solutions have been showcased as vehicles for reducing this stress, ranging from lifecycle costing through to waste reduction strategies, carbon assessment and “green” environmental assessment tools to name but a few. However, this paper argues that whilst some of these (intervention strategies) may have had some positive effects, the main challenge rests with people—inter alia, the key decision-makers and leadership structures with the “position power” to effect change. Acknowledging this as a supposition, this paper uses three discreet construction organisations engaging in offsite construction as a micro-study (cf. cross-case study) to evaluate sustainability perceptions. In doing so, it focuses specifically on sustainability practices and business processes underpinning technology (adoption, absorption and diffusion), including the perceptions of different stakeholders involved in each of these three companies. In total, 30 respondents from three organisations (cases) participated in this study, representing three tiers of management (top, middle and first line). Priority areas are highlighted, along with the reasons supporting these perspectives. Findings from this work present a new technology diffusion sustainability model for offsite construction. This model identifies sustainability causal links, super catalysts, actuators, barriers, forces and facilitators. More importantly perhaps, this work presents a clear case for “conjoined thinking” in order to instill a collective mindset change and common purpose for those wishing to evidence offsite sustainability.
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Offsite construction has become popular in recent times due to the numerous benefits it offers compared to traditional construction methods. This paper explores the different offsite construction methods, the motivations for adopt...
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Offsite construction has become popular in recent times due to the numerous benefits it offers compared to traditional construction methods. This paper explores the different offsite construction methods, the motivations for adopting these approaches, and the cost-effectiveness of these methods in the UK housing sector using multiple case studies. Firstly, the literature and data were obtained from various sources including professional body reports, industry reports, government websites, and journal articles. Following the review, twelve completed housing projects from the UK which used offsite construction approaches were analyzed. The review of these projects showed that different offsite methods were used in these projects. These include Structural Insulated Panels (SIPs), Timber Frames, Precast Concrete, Steel Frames, Volumetric Construction, Gyproc Habito Plasterboards, and Light Gauge Steel (LGS) technology. The key motivations for adopting offsite construction in these projects include the speed of construction, durability of the products, aesthetic considerations, thermal quality, low air leakage requirements, and quality of construction. Of the 12 cases, only two recorded a higher cost for the offsite construction method compared with the alternative using traditional approaches. The outputs of this paper provide evidence-based strategies which would inform practitioners on the best practices for adopting offsite construction methods and what to expect.
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Although offsite construction (OSC) has emerged as a promising solution to low productivity issues in the construction industry, knowledge for effective management of OSC projects is yet to be explored and developed further. To en...
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Although offsite construction (OSC) has emerged as a promising solution to low productivity issues in the construction industry, knowledge for effective management of OSC projects is yet to be explored and developed further. To enhance our understanding of the landscape of the current OSC management knowledge, this study identified and reviewed 83 operation-level OSC management papers. By mapping the papers on three dimensions (i.e. OSC project type, project phase, and management area), this review sheds light on the knowledge areas addressed more frequently than the other areas over time in a detailed manner. The review also shows that papers on planning, manufacturing, maintenance phases and schedule, resources, and stakeholder management areas have a relatively large number of citations, implying a great interest in these research areas. Finally, the review discusses that substantial research work is still required in the areas of OSC execution strategy, emerging technologies in offsite manufacturing and schedule management, internet of things (IoT)-based material logistics planning and tracking, building information model-based visualization and decision support, and social and environmental effects of stakeholder engagement in OSC projects.
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