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Construction-Oriented Design for Manufacture and Assembly (DfMA)
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Guidelines
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Tan Tan
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, Weisheng Lu
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, Gangyi Tan
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, Fan Xue
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, Ke Chen
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, Jinying Xu
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, Jing Wang
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, and
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Shang Gao
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This is the peer-reviewed, post-print version of the paper:
Tan, T., Lu, W., Tan, G., Xue, F., Chen, K., Xu, J., Wang, J. & Gao, S. (2020).
Construction-Oriented Design for Manufacture and Assembly (DfMA) Guidelines.
Journal of Construction Engineering and Management, in press.
This material is shared under the permission of ASCE, and may be downloaded for
personal use only. Any other use requires prior permission of ASCE. The official version of
this paper may be accessed at LINK_TO_INSERT
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Abstract
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The pursuit of modern product sophistication and production efficiency has bolstered Design
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for Manufacture and Assembly (DfMA) around the world. Being both a design philosophy and
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a methodology, DfMA has existed in manufacturing for decades. It is coming into vogue in
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construction as a potential solution to the industry’s lackluster productivity amid enduring
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exhortation of cross-sectoral learning. However, many studies of DfMA in construction are still
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simply following the DfMA guidelines developed from manufacturing without adequately
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considering important differences between the two sectors of construction and manufacturing.
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This study aims to develop a series of construction-oriented DfMA guidelines by adopting a
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mixed-method approach. It critiques existing DfMA guidelines in relation to the characteristics
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of construction, and further argues that construction-oriented DfMA should consider five
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fundamental aspects: contextual basis, technology rationalization, logistics optimization,
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component integration, and material-lightening, either individually or collectively. A case study
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is then conducted to substantiate and verify the feasibility of these guidelines. This research
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sheds new light on the cross-sectoral learning of DfMA from manufacturing to construction.
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The guidelines can be used as the benchmark for the evaluation of manufacturability and
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1
Ph.D. Student, The Bartlett School of Construction & Project Management, University College London, UK, e-mail:
tan.tan.17@ucl.ac.uk;
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Professor, Corresponding Author, Department of Real Estate and Construction, The University of Hong Kong, Hong Kong
SAR, e-mail: wilsonlu@hku.hk, Tel.: +852 3917 7981;
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Professor, Department of Architecture, Huazhong University of Science and Technology, China, tan_gangyi@163.com;
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Assistant Professor, Department of Real Estate and Construction, The University of Hong Kong, Hong Kong SAR, e-mail:
xuef@hku.hk;
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Associate Professor, Department of Construction Management, Huazhong University of Science and Technology, China, e-
mail: chenkecm@hust.edu.cn;
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Ph.D. Candidate, Department of Real Estate and Construction, The University of Hong Kong, Hong Kong SAR, e-mail:
jinyingxu@connect.hku.hk;
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Ph.D. Candidate, Department of Real Estate and Construction, The University of Hong Kong, Hong Kong SAR, e-mail:
jingww@connect.hku.hk;
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Lecturer, Faculty of Architecture, Building and Planning, The University of Melbourne, Australia, e-mail:
shang.gao@unimelb.edu.au.
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assemblability in practice. It also opens up a new avenue for further DfMA studies in
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construction.
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Keywords: Design for manufacture and assembly; Architecture; Construction; Manufacturing;
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Assembly; Design guidelines
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Introduction
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Design for Manufacturing and Assembly (DfMA) is both a design philosophy and methodology
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whereby the downstream processes of manufacturing and assembly are considered when
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designing products (Boothroyd, 2005). Originating from the manufacturing industry, DfMA
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suggests a systematic design process that integrates the production experience into the product
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design (Corbett et al., 1991; Kuo et al., 2001; Harik and Sahmrani, 2010). It has two components:
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design for manufacture (DfM) and design for assembly (DfA). DfM compares selected
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materials and manufacturing processes for the parts, determines the cost impact of those
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materials and processes, and finds the most efficient use of the component design (Ashley,
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1995), while DfA addresses the means of assembling the parts (Bogue, 2012). Altogether,
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DfMA represents a shift from a traditional, sequential approach to a non-linear, reiterative
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design methodology. Since its emergence during World War II and flourishing in the
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1960s~1970s, numerous DfMA guidelines (e.g., Boothroyd, 2005; Swift and Brown, 2013;
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Bogue, 2012; Emmatty and Sarmah, 2012) have been developed to help designers to operate
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this design philosophy to improve designs, productivity and profitability (Gatenby and Foo,
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1990; Kuo et al., 2001). More recently, a ‘Design for Excellence’ (DfX) approach has
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developed where the ‘X’ may denote excellence in any aspect, including testability, compliance,
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reliability, manufacturability, inspection, variability, and cost (Maskell, 2013; Huang, 2012).
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DfMA is now beginning to come into vogue in the construction industry. Notably, the Royal
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Institute of British Architects (RIBA) (2013) published a DfMA overlay to its Plan of Work
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2013. The governments of the UK, Singapore, and Hong Kong have all published DfMA guides
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or emphasized its importance in construction. Industry giants such as a Laing O’Rourke (2013)
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and Balfour Beatty (2018) have even indicated that they consider DfMA to be the future of
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construction.
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Some terminologies need to be clarified here. According to Dainty et al. (2007), precisely what
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constitutes construction is subject to a range of boundary definitions. There are narrow and
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broad definitions of construction (Pearce, 2003). The narrow definition of construction focuses
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on onsite assembly and the repair of buildings and infrastructure. Contrastingly, the broad
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definition of construction could include quarrying of raw materials, manufacture of building
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materials, sale of construction products (Dainty et al., 2007), and professional services such as
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architectural design, urban planning, landscape architecture, engineering design, surveying,
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construction-related accountancy, and legal services (Jewell et al., 2014). All the above sub-
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sectors can be allocated a four-digit U.S. SIC (Standard Industrial Classification) code, which
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is in accordance with the United Nation’s International SIC or the U.K. SIC (Lu et al., 2013).
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At the risk of oversimplification, this study treats upstream architecture and engineering
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activities as “design”, and downstream onsite activities as “construction”. Onsite construction
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is traditionally conducted using cast in-situ; it is a combination of fabrication and assembly
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(Ballard and Howell, 1998). In recent years, the global construction industry has seen a number
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of initiatives to minimize onsite construction, shifting it to downstream offsite
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“manufacture”/fabrication but bringing it back onsite for “assembly” (Duncan in RIBA 2013).
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To understand the concept of DfMA in construction, one must position it in the heterogeneous
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context of construction and be cognizant of the relationships between architecture, engineering,
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construction, manufacturing, and assembly therein.
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One can also understand the DfMA trend against the background of global construction, which
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is characterized by ever-heightened product sophistication, sluggish productivity growth,
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increasing influence of cross-sectoral learning, and emerging technological advancements in
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virtual design and construction. Production inefficiency in construction has been criticized in a
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succession of influential UK-based industry reports, including ‘Constructing the Team’
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(Latham, 1994), ‘Rethinking Construction’ (Egan, 1998), ‘Never Waste a Good Crisis’
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(Wolstenholme et al., 2009), and more recently in The Economist (2017) comparing
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construction productivity with its manufacturing and agriculture counterparts. Construction has
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been accused of being ‘adversarial’, ‘ineffective’, ‘fragmented’, and ‘incapable of delivering’,
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with an appalling backwardness that should be improved, e.g., through industrial structure or
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organizational culture. Increasingly, it is exhorted that construction should look to and learn
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from highly productive industries such as advanced manufacturing (Camacho et al., 2018).
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Lean construction (Koskela, 1992) is typically advocated as a result, as is DfMA.
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The exploration of production innovation, in particular offsite construction, has provided an
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unprecedented opportunity for DfMA. It is the similarities between offsite
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construction/prefabrication and manufacturing that have pushed DfMA to the fore of the
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industry’s cross-sectoral learning and innovation agenda. In addition, emerging technological
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advancements, such as Building Information Modelling (BIM), 3D printing, the Internet of
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Things (IoTs), and robotics provide the construction industry, DfMA in particular, new entry
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points for manufacturing knowledge and efficiency improvement.
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However, current DfMA practices in construction still, by and large, follow DfMA guidelines
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developed in a manufacturing context without sufficiently considering the differences between
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construction and manufacturing. For example, DfMA procedures in Boothroyd (2005) consider
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DfA and DfM but not the downstream logistics and supply chain (LSC), which plays a critical
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role in offsite prefabrication construction. Some construction DfMA guidelines proposed, e.g.,
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Gbadamosi et al., (2019), Kim et al., (2016), and Banks et al. (2018), originate more or less
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from manufacturing-oriented guidelines. While inspiring, some of these guidelines are not
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necessarily a good fit with construction’s characteristics, leading to an inability to improve
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manufacturing and assembly. Some guidelines are proposed in a fragmented fashion without
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necessarily forming an organic whole, leading to a lack of comprehensiveness, or “easy to use”
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throughout the building process. The RIBA, in recognizing the potential of DfMA in
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construction, added an overlay of DfMA to its time-honored Plan of Work. Following RIBA’s
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vision (2013, p. 24), much “soft-landing” work remains to implement DfMA in construction.
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Partly responding to this call for “soft-landing” work, this paper aims to facilitate the
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implementation of DfMA in construction by proposing a series of construction-oriented DfMA
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guidelines. It has three objectives: (1) to identify the differences between manufacturing and
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construction; (2) to propose a series of construction-oriented DfMA guidelines; and (3) to
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evaluate the proposed DfMA guidelines by using empirical evidence. These objectives are
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achieved using a mixed-method approach including literature review, comparative analysis, and
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case study. The remainder of this paper is organized into six sections. Section 2 presents basic
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knowledge such as the origin, concept, and general applications of DfMA. Section 3 describes
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the research methods adopted. Section 4 introduces the development of DfMA guidelines for
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construction projects by adapting existing DfMA guidelines to fit the characteristics of the
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design process and the final product in construction. In Section 5, the developed DfMA
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guidelines are evaluated through empirical evidence from research and practice. The last two
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sections present discussions and a conclusion, respectively.
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An overview of Design for Manufacture and Assembly
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DfMA originated in the weapon production processes developed by Ford and Chrysler during
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World War II. Formal approaches to DfM and DfA emerged in the late 1960s and early 1970s
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when the UK published The Management of Design for Economic Production standard in 1975.
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The academic exploration of DfMA can be traced back to the 1970s when Boothroyd and
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Dewhurst conducted research and practice in this area. Boothroyd (1994) described the
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shortcomings of an “over the wall” design approach and suggests the application of DfMA
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methodology to making production knowledge available to designers. Hamidi and Farahmand
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(2008) suggested that DfMA implementation needs a feedback loop between design and
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manufacturing; for example, with a design being checked by the manufacturer to identify
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potential problems or waste in the downstream processes of manufacturing and assembly.
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Since its adoption in manufacturing, DfMA has helped many companies increase their profits
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through optimized design (Gatenby and Foo, 1990; Kuo et al., 2001). Several guidelines have
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been consolidated to help designers reduce difficulties in manufacturing and assembling a
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product. Examples include minimizing the number of parts (Kuo et al., 2001; Eastman, 2012;
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Bogue, 2012) and searching for the most efficient use of modular design (Ashley, 1995). Some
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analytical tools have also been developed for designers to evaluate their proposed design from
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the perspectives of manufacturing and assembly difficulties. Although these
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guidelines/principles have been developed from various reference points, they share substantial
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similarities, with minimization, standardization, and modular design emerging as key DfMA
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principles.
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The importance of considering the production process in the design stage is also recognized by
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the construction industry. Architectural and engineering design have never been a pure art; there
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is a long-standing architectural philosophy of “form follows function” (Goulding et al., 2015)
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whereby form, functions, quantity, and buildability should be considered in design. Design
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optimization has been advocated. But DfMA is different in that it consciously highlights the
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downstream processes of manufacturing and assembly. With its success in the manufacturing,
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civil aviation, auto, and other industries, researchers have suggested the implementation of
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DfMA in construction to harvest benefits including time reduction, cost minimization, and
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achieving customer satisfaction. Although DfMA has only recently been introduced to
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construction, some DfMA-like thinking precedes it. For example, Fox et al. (2001) proposed a
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strategy for DfM application to buildings, and Crowther (1999) proposed design for
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disassembly as the final step of DfA in construction for life cycle assemblability. More recently,
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Yuan et al. (2018) integrated BIM and DfMA to develop the concept and process of DfMA-
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oriented parametric design, and Arashpour et al. (2018) explained DfMA guidelines in modular
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prefabrication of complex façade systems. Chen and Lu (2018) also highlighted the application
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of DfMA in the façade system through a case study. In addition to this research work, industrial
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reports such as Laing O’Rourke (2013), Balfour Beatty (2018), and RIBA’s DfMA overlay
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(2013) have helped popularize DfMA in construction.
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Despite support from both academia and industry, DfMA has yet to achieve fervent
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implementation in construction because of problems related to new design system and
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standardization, fragmentation, multi-party coordination, and lack of proper design guidelines
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(Jin et al., 2018; Gao et al., 2018). Few studies, if any, have discussed the differences of DfMA's
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guidelines between manufacturing and construction. Indiscriminate introduction of guidelines
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from a manufacturing to construction may not increase productivity, and will definitely pose
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additional uncertainties and risks (Paez et al. 2005).
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Research methods
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This study adopts a four-step research design, as shown in Figure 1. The first step is to review
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fundamental guidelines of DfMA widely adopted in the manufacturing industry. These
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guidelines are retrieved from authoritative publications, including academic papers and reports.
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Some of these guidelines can be applied to the design of building components for efficient
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construction, but others cannot. Therefore, the second step is to generate a tentative set of DfMA
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guidelines applicable to construction. This process is delivered based on an understanding of
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the similarities and differences between construction and manufacturing. The third step is to
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