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New Design for Assembly (DfA) methodology for large and heavy parts assembled on site
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Abstract
A literature review on the assembly design methodologies (DfA) oriented to the assembly of large and heavy parts, reveals the need to develop a DfA methodology. In addition, the lack of DfA evaluation methods for on-site assembly is also observed. The most widespread DfA methodologies are more oriented toward the improvement of factory assembly processes, where the assembly processes are well defined and standardised. Hence, this article presents a new methodology for the design of assemblies with large and heavy parts on site, called OSIA (On-Site Installation Analysis). OSIA methodology aims to provide data (indicators). On the one hand the theoretical basis of the OSIA methodology is based on three key concepts: i) analysis of assembly operations similar to the one used by the SMED methodology; ii) generic implementation process of DfA methodologies; and, iii) compilation of assembly operation times and estimation of standard times per operation. On the other hand, the steps in the implementation of the methodology are summarized in: i) database development with assembly operations and standard times; ii) assembly operations analysis; iii) calculation of assembly time; and iv) product optimization. In this way, OSIA methodology supports the designer in the specification phase, detailed design phase and in the redesign processes, providing the designer with indicators that make it possible to optimise the design of the parts and reduce the assembly operations of a product on site. Keywords: Design for assembly; Design for assembly for large and heavy parts; Design for assembly on site; Design for installation.
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The increasing gap in shopfloor operators’ skillset regarding advanced information and communication technologies along with workforce’s diversity require a cognitive system bridging such technical gaps in order to address evolving production demands and satisfy the human need for self-fulfillment and self-actualization at work. This study discusses on a two-level collaborative filtering approach to improve the distribution of information content provided to an operator for completing a manufacturing activity while considering his or her feedback. A prototype implementation is evaluated in a case study related to the operator’s job rotation on a shopfloor that involves multiple workstations and tasks.
The assembly process is sometimes blocked due to excessive dimension deviations during large-scale assembly. It is inefficient to improve the assembly quality by trial assembly, inspection, and accuracy compensation in the case of excessive deviations. Therefore, assemblability prediction by analyzing the measurement data, assembly accuracy requirements, and the pose of parts is an effective way to discover the assembly deviations in advance for measurement-assisted assembly. In this paper, a coordination space model is constructed based on a small displacement torsor and assembly accuracy requirements. An assemblability analysis method is proposed to check whether the assembly can be executed directly. Aiming at the incoordination problem, an assemblability optimization method based on the union coordination space is proposed. Finally, taking the space manipulator assembly as an example, the result shows that the proposed method can improve assemblability with a better assembly quality and less workload compared to the least-squares method.
The pursuit of modern product sophistication and production efficiency has bolstered Design for Manufacture and Assembly (DfMA) around the world. Being both a design philosophy and a methodology, DfMA has existed in manufacturing for decades. It is coming into vogue in construction as a potential solution to the industry’s lackluster productivity amid enduring exhortation of cross-sectoral learning. However, many studies of DfMA in construction are still simply following the DfMA guidelines developed from manufacturing without adequately considering important differences between the two sectors of construction and manufacturing. This study aims to develop a series of construction-oriented DfMA guidelines by adopting a mixed-method approach. It critiques existing DfMA guidelines in relation to the characteristics of construction, and further argues that construction-oriented DfMA should consider five fundamental aspects: contextual basis, technology rationalization, logistics optimization, component integration, and material-lightening, either individually or collectively. A case study is then conducted to substantiate and verify the feasibility of these guidelines. This research sheds new light on the cross-sectoral learning of DfMA from manufacturing to construction. The guidelines can be used as the benchmark for the evaluation of manufacturability and assemblability in practice. It also opens up a new avenue for further DfMA studies in construction.
This paper describes a new design methodology for long life and large size (Ll-Ls) product assembly, which has been developed modifying and merging existing Design for Assembly (DfA) methodologies to adapt them to the particularities of this kind of products. These goods are often formed by different large and heavy subcomponents that need to be assembled and commissioned on field, which require the use of several people or special machinery, aspects that are not considered in traditional DfA methodologies. The new methodology, through a Lucas-Hull DfA methodology based approach, gives the chance to evaluate and enhance different design options in the design phase without the need to construct and test prototypes, which are usually quite expensive for this typology of products. An in-house tool has been created to help the designer in the evaluation of different options, where the identifications of the critical features that penalize the assembly of Ll-Ls products are easily identifiable. A case study has been carried out over a solar tracker to test the new approach where design efficiency has been optimized up to 20.4 percentage points through the advices given by the methodology. This means that the optimized design can save up to the 22.8% of the assembly cost in an standard 4.6MW plant, which usually has up to 850 solar trackers. Yet, although the results are really promising, the need to study and add logistic factors to the methodology for this kind of products has been proven, as involved high costs in the whole installation process need to be considered
Design for Assembly (DFA) methodologies help the designer to take into account the assembly process during the development phases of a product (specifications, conceptual design and detailed design), thus improving the assembly process of the product. After a bibliographic review, it is verified that the most extended DFA methodologies are: Boothroyd-Dewhurst method, Lucas method, Hitachi AEM method and Modified Westinghouse method. All these methodologies help to achieve improvements in some of the development phases, but none of them assist the designer in all the phases of the process.
This article presents a DFA methodology that considers the assembly process of a product during all the phases of its development (DFA-SPDP). For this purpose, DFA-SPDP method is created from the four most widespread methodologies. This methodology brings together the main quantitative parameters of the four methodologies in a single method. As a conclusion, applying DFA-SPDP method, the designer is supported throughout the process of developing a product, with information equivalent to that resulting from the application of the four methodologies.
The fast development of smart sensors and wearable devices has provided the opportunity to develop intelligent operator workspaces. The resultant Human-Cyber-Physical Systems (H-CPS) integrate the operators into flexible and multipurpose manufacturing processes. The primary enabling factor of the resultant Operator 4.0 paradigm is the integration of advanced sensor and actuator technologies and communications solutions. This work provides an extensive overview of these technologies and highlights that the design of future workplaces should be based on the concept of intelligent space.
Design-for-Assembly (DfA) and Conceptual DfA criteria are used in the generation of cost-effective assembly sequences for complex products. The design freedom suggests optimal solutions in the assembly time minimization problem regardless costs and issues about materials and manufacturing processes selection. The goal of this approach is to investigate how the application of the conceptual DfA affects the material and manufacturing costs (Design-to-Cost). A complex product (tool-holder carousel of a CNC machine) is used as a case study. The outcome is an approach to support designers and engineers in the re-design process for the product development and cost reduction.
Design For Assembly (DFA) is a tool to evaluate the design of parts and the products assemblability. Additionally, DFA is a key tool to reduce both cost and assembly time. DFA includes a set of techniques and procedures that, when applied properly, makes the product assembly more efficient. Assembly takes between 20% and 60% of production time, and represents between 25% and 75% of the total cost of the manufactured products. Existing techniques consider weight and size restrictions to assess the design features of the products. All those components not considered within the weight and size constraints are qualified in equal way. For the scope of this research large and heavy parts are defined as parts that measure above one meter and weight from five kilograms to five tons. Most products of large size have assemblies and subassemblies. Additionally there are a number of processes for handling an assembly of large and heavy components. Despite the information identified, further research focused to improve the knowledge in assembly methods is needed. This paper presents the state of-the-art in the assembly of large and heavy components analysis and to be a reference for future research.
In this paper, emerging technologies in the automotive assembly are discussed, along with techniques used in the vehicle assembly plants. The discussion involves technologies directly dealing with assembly processes such as handling, joining, human resources etc. as well as with supporting systems, mainly the information technologies. An overview of the existing technologies is provided. The assembly systems are unable to cope with the requirements of mass customization and need to be enriched with new technologies for a higher flexibility potential. Concepts integrating various new technologies into supporting both automated and human based assembly operations are presented and discussed versus this identified inability for mass customization. Future assembly plants need to utilize flexibility systematically, both for the system design and its operation. For this purpose, a close loop approach is discussed.
The benefits of integrated design and manufacturing systems in mid to high volume production are widely accepted. The low production volume, large component size and high complexity product domain is less well served by this technology. Examples of this kind of product are machine tools, ships, aircraft and buildings. Design for assembly techniques are a method by which design and manufacture can be integrated and aid the realization of full-process concurrent engineering. Quantifies the significance of this product domain to the UK economy, describes the particular nature of these designs for assembly processes, reviews existing work in the field and specifies the problems encountered. Defines an industrial and academic solution programme. Proposes an integrated approach to applying design for assembly to this repetitive direct engineering domain.
Bringing together the expertise of worldwide authorities in the field, Design for X is the first comprehensive book to offer systematic and structured coverage of contemporary and concurrent product development techniques. It features over fifteen techniques, including: design for manufacture and assembly; design for distribution; design for quality; and design for the environment. Alternative approaches and common elements are discussed and critical issues such as integration and tradeoff are explored.
The transition within business from a linear to a circular economy brings with it a range of practical challenges for companies. The following question is addressed: What are the product design and business model strategies for companies that want to move to a circular economy model? This paper develops a framework of strategies to guide designers and business strategists in the move from a linear to a circular economy. Building on Stahel, the terminology of slowing, closing, and narrowing resource loops is introduced. A list of product design strategies, business model strategies, and examples for key decision-makers in businesses is introduced, to facilitate the move to a circular economy. This framework also opens up a future research agenda for the circular economy.
The Assemblability Evaluation Method (AEM) is an effective tool developed by Hitachi, Ltd. to improve design quality for better assembly producibility. The AEM has been widely used by the Hitachi Group as well as by more than 20 other well-known companies around the world. Using this method, in the early design stage, product design quality is analyzed quantitatively and weaknesses in the design's assembly producibility are highlighted. In addition, the effects of design improvements are confirmed with respect to assembly cost. Through these activities, design improvement is realized. In order to improve the functionality and the accuracy of the method to allow a wide variety of use, the extended AEM has been developed. Based on a constructed product and process model, a new evaluation system has been developed and part-based cost estimation has been realized. In this paper, the concept, theory, evaluation procedure, and accuracy of the extended method are described.
Traditional Design for Assembly methods are limited to part sizes between a few millimeters to a few tens of centimeters in overall size and to part weights under a few kilograms. Parts in the range of a meter in overall size and weighing a few tens of kilograms are examined in this paper. An experimental plan separates weight, mass, and inertia and correlates these properties with assembly difficulty and time. When windage, part flexibility, and operator fatigue are absent, a set of three parameters serve to model these effects on human assembly performance. Adaptation of this result is made to extend a Design for Assembly methodology.
The need for a method of estimating assembly times for large products during the product design phase is discussed. An approach to the development of a database of part acquisition and handling times is described and some preliminary results are presented. Comments and conclusions are made regarding the feasibility of the proposed approach.
The understanding of manual dexterity is seen as a key element in the design of products and processes for automated, flexible assembly systems. A human-centered definition of dexterity based on human motor capacity is introduced and applied in the form of a special slide-rule. A guide for using the slide-rule is presented with examples.
The product design that is best for function, for manufacturing, for assembling and for servicing results in the best product. Such a design is an ideal so difficult to achieve that it has to be tackled in stages, which ultimately have to be successfully integrated. The stages of Design for Manufacture (DFM) and Design for Assembly (DFA) combine towards that integration in the form of Design for Manufacture and Assembly (DFMA). Some broad guidelines for DFMA are given in Table I.
The results of the applications of design for assembly techniques to two typical designs are presented. Consideration is given
to the total product cost and it is found that major cost reductions can be achieved even when assembly costs are relatively
small. It is also found that assembly automation becomes more difficult to justify as a product design is gradually improved.
It is becoming increasingly apparent that the effective and efficient use of robotic and automated assembly techniques requires that the design of the product is compatible with these assembly systems. The basis for establishing a set of design rules for robotic and automated assembly are presented together with some more generalised design guidelines. Consideration is given to the presentation of the product design information to the designer using computer aided techniques.
First Page of the Article
Manufacturing assembly handbook
- B Lotter
B. Lotter, Manufacturing assembly handbook. London:
Butterworths, 1989.
Connection Design for Easy Assembly On-Site Method to Design and Evaluate Structural Connections in Industrial Construction
- E Jürisoo
- R Staaf
E. Jürisoo and R. Staaf, "Connection Design for Easy Assembly
On-Site Method to Design and Evaluate Structural Connections in
Industrial Construction," Chalmers University of Technology,
2007.
Design for Assembly Methods for Large and Heavy Plates: An experimental Design
- Y Wongwanich
Y. Wongwanich, "Design for Assembly Methods for Large and
Heavy Plates: An experimental Design," Virginia State University,
2001.
Design for manufacture and assembly in construction: a review Changing cities View project Content analysis of construction documents using semantic similarity models View project
- S Gao
- R Jin
- W Lu
S. Gao, R. Jin, and W. Lu, "Design for manufacture and assembly
in construction: a review Changing cities View project Content
analysis of construction documents using semantic similarity
models View project," Build. Res. Inf., vol. 48, no. 5, pp. 538-550,
2019.
Expert system aids design for assembly
- K G Swift
K. G. Swift, "Expert system aids design for assembly," Assem.
Autom., vol. 9, no. 3, pp. 132-136, 1989.
DFA2-en metod för att utveckla monteringsvänliga produkter. Institutet för verkstadsteknisk forskning
- K Rapp
- J Von Axelson
K. Rapp and J. Von Axelson, DFA2-en metod för att utveckla
monteringsvänliga produkter. Institutet för verkstadsteknisk
forskning, 2003.
How to Implement Lean Manufacturing
- L Wilson
L. Wilson, How to Implement Lean Manufacturing. McGraw Hill,
2010.
An industrial Internet of things based platform for context-aware information services in manufacturing E-CUSTOM-A Web-based Collaboration System for Mass Customization (FP7-2010-NMP-ICT-FoF) View project SPARE (Sensor-based product monitoring system to s
- K Alexopoulos
- K Sipsas
- E Xanthakis
- S Makris
K. Alexopoulos, K. Sipsas, E. Xanthakis, and S. Makris, "An
industrial Internet of things based platform for context-aware
information services in manufacturing E-CUSTOM-A Web-based
Collaboration System for Mass Customization (FP7-2010-NMP-ICT-FoF) View project SPARE (Sensor-based product monitoring
system to s," Int. J. Comput. Integr. Manuf., vol. 31, no. 11, pp.
1111-1123, 2018.