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Design for Manufacturing and Assembly (DfMA) is a consolidated engineering activity that suffers a real integration with 3D CAD systems. DfMA principles are currently applied downstream of the 3D m...

The paper presents the methodology of designing the production process of a new product from the point of view of the criterion of the assembly operations technology (Design for Assembly - DFA) in the automotive industry. The article describes methods and techniques used during the implementation of a new product into production. The impact of the methods on improving the assembly technology of a complex product is described. Suggestions for improving for unit and small series production are presented.

Product packaging has a huge impact on the efficiency of supply chain activities. In this research, the concept of Design for Assembly (DFA), proved in earlier studies to be effective at improving product manufacturing operations, is applied to the packaging system. We formulate the packaging system as a mathematical model for three different objectives. With respect to the continual rise in attention paid to sustainability, this research adds sustainability as one of the primary objectives. A case study demonstrates that the proposed model can achieve desired results and reveals a level of consistency among the three objectives. In addition to the application of DFA concepts to a packaging system, the contributions of this research lie in the development of a mathematical model (using integer programming and goal programming) for calculating the cost, handling time, and sustainability of the objectives in line with the design needs of the multi-level packaging size from the perspective of a supply chain to provide a range of solutions offering increased options for firms.

Due to the current and highly competitive industrial scenario, the technology-oriented organizations have been making routine adjustments to the conventional IPDP, in order to seek more profitable business models. Identifying the product functions, as well as its importance - perceived by the consumer - and being able to associate this information with manufacturability and assembly aspects, is fundamental to achieve more competitive, low-cost and higher quality products. This article objective is to evaluate this method concept, applying it in an industrial project. In order to assess the method within the complete integrated product development process (IPDP), the activities related to the conceptual and preliminary phases of the project delineated this article limits. This study selected a subgroup of the white goods industry, where first the traditional models of VE were applied in the conceptual design phase. Subsequently, the classic DFA models were applied in the preliminary design phase. Thus, it was possible to apply the proposed iterative method, where the alternatives generated with the DFA were cyclically re-evaluated, function by function, in the previous stage of value analysis. With this, this study came to the method assessment, its gains and limitations. Then, the original design was compared with the solution after the proposal application, without the method used. Finally, this study verified the influence of the method on the balance between the value and the cost of each function, in addition to the direct comparison of the solution final cost with the version without the method application. Among the results, this article presents a report showing the method viability, its particularities, impacts, and limitations.

CNC Laser (Computer Numerical Control) adalah alat yang memiliki fungsi untuk mengukir/mencetak berbagai tulisan dan kaliqrafi secara otomatis berdasarkan media yang digunakan seperti Acrilic, Fiber, Almunium, dan kayu. Perancangan CNC laser menggunakan metode Design For Assembly Boothroyd (DFA), G-Code , dan Closed Loop System (Loop Tertutup). Kelebihan metode DFA yaitu mengestimasikan pengurangan waktu perakitan. Metode G-Code lebih ke menyatukan gerakan yang akan di lakukan mesin, seperti bergeser ke titik A, titik B. Kemudian pada metode Closed Loop System (Loop Tertutup) bekerja mengirim sinyal umpan balik ke pengendali untuk mengecilkan kesalahan sistem. Hasil pengujian dari komponen pada masing-masing alat secara keseluruhan berupa input dan output menjadi kesatuan alat mesin CNC laser cutting dan engraver . Software GRBL dihubungkan pada CNC shild . GRBL mengirim G-Code ke arduino dan menerjemahkan isi dari G-Code satu persatu untuk menghasilkan pergerakan motor stepper dan cahaya laser . Telah didapatkan sistem pengontrolan mesin laser engravir yang bisa menggerakkan mesin kearah dua sumbu X dan Y, yang tersusun dari beberapa komponen yaitu komputer, kontroler arduino nano, motor stepper , laser module , power supplay dan emergency stop. Pengujian laser engraver dilakukan dengan medium plywood dan berbagai pola gambar. Hasil pengujian menunjukkan alat dapat bekerja sesuai dengan pola gambar yang ada. CNC Laser (Computer Numerical Control) tools that have a function to automatically engrave / print various writings and kaliqrafi based on the media used such as Acrilic, Fiber, Aluminum, and wood. CNC laser design uses the Design For Assembly Boothroyd (DFA), G-Code, and Closed Loop System (Closed Loop) method. The advantage of the DFA method is that it estimates the reduced assembly time. The G-Code method is more about unifying the movements that the machine will do, such as moving from point A to point B. Then the Closed Loop System method works to send a feedback signal to the controller to minimize system errors. The test results of the components on each tool as a whole are in the form of input and output into a unity of the CNC laser cutting and engraver machine tool. GRBL software is linked to the CNC shild. The GRBL sends the G-Code to the Arduino and translates the contents of the G-Code one by one to produce stepper motor movement and laser light. A schematic of a laser engraving machine control system that is able to move the machine towards two axes X and Y, which is composed of several components, namely a computer, Arduino nano controller, stepper motor, laser module, power supply and emergency stop. Laser engraver testing was carried out using plywood and various image patterns. The test results show that the tool can work in accordance with existing image patterns.

Sustainable medical device design in the context of a health emergency is an unexplored area of research. The urgency to save lives implies that eco-design strategies may not be considered. However, some of these strategies could lead to cost and manufacturing time reduction, implying that more units could be produced, and more patients reached. This paper aims to provide feasible eco-design strategies that could be shared with the stakeholders involved in the product design and manufacturing of emergency ventilators for Covid-19. The objective is to help tackle the Covid-19 crisis in a more sustainable way, and increase the access to healthcare of people requiring assisted ventilation during the health emergency. Adopting a Whole Systems Design perspective (Blizzard and Klotz, 2012), this research has applied the Holistic Design Framework (Aranda-Jan et al., 2016) and the Eco-design Strategy Wheel (Brezet and Hemel, 1997) to elaborate preliminary strategies aligned with the emergency design objectives. Different design for sustainability tools, approaches and principles have been used to discuss, analyse and provide a final set of recommended strategies. These can be grouped in four categories: design for assembly, extension of product lifetime, usage of materials, and lean manufacturing. Despite further efforts are needed to overcome implementation challenges identified during the definition of strategies, it is expected that the above recommendations can be put in practice in a short-term to bring benefits in terms of better environmental impact, lower costs and total manufacturing time.

The optimization of the assembly phase, in complex products, is a challenging phase and it need to be handled in the early phase of product development (i.e., conceptual design). Several methods have been developed to assess the assemblability of product at the conceptual design phase, however, the most critical aspect concerns the possibility to derive design guidelines starting from the results of assemblability analysis. In this context, the present work aims at defining a methodology able to retrieve design for assembly and installation guidelines starting from the analysis of a given product architecture at the conceptual design phase (loop-back of the design for assembly method). The developed method makes use of matrices and vectors to provide a list of design actions that affect the product assemblability including a ranking of their impacts on the final design. The methodology was used to retrieve and select design guidelines in the context of aircraft manufacturing. The case study (cabin equipping of commercial aircraft) provides interesting results in the identification and implementation of design guidelines to improve the aircraft architecture at the conceptual level.

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.

Product variety is a growing trend of offering highly configurable products, but increases complexity costs throughout the entire product lifecycle. Modularization makes managing variety-induced complexity and ensuring profitable production possible. Unfortunately, the interfaces between modules represent joining domains and lack modularization and commonalization solutions. Meanwhile, joining element design finds increasingly more support from automation resulting in optimized solutions for individual product variants. Besides, continuous product development implies sequentially designed product variants that cause ambiguous and unnecessary design iterations for joining element design. This paper presents a five-step methodology to modularize joining elements in early product development, while balancing variety-induced complexity and production costs. It reduces complexity by commonalizing joining elements over product variants. The methodology unifies joining technologies, clusters joining locations and proposes an approach to increase modularity by balanced addition of joining elements.

Assembly is currently a very important element in the production process. We can also define it as the last stage in the production process. It greatly affects the quality of the product and especially the time needed to make the final product. The presented article is a contribution to the improvement of methods in the field of technological design of the product in terms of assembly, resp. in the field of methodologies known as DFA, which in its entirety means Design of Assembly. The general objective of improving the assembly process is in most cases reducing the cost of the product. With the gradual development of the technologies coming into practice, companies are focusing mainly on improving the elements of assembled products of the assembly system. This state can be achieved, for example, by reducing the number of components, so the complexity and laboriousness of the assembly will be radically reduced. This in turn leads to a decrease in unit assembly costs. Proper assembly settings can help a company succeed in the competition and thus contribute to a stable position of the company in the market. The aim of the article is to find the other objective indicators of assembly quality evaluation.

Today, Prefabrication is considered as one of the concepts of industrialization in response to the growing needs of human societies for development. It is particularly important to address this concept in mass housing projects. The most important goals in adopting the prefabrication approach are to increase construction speed and quality and reduce costs. A review of the literature on prefabrication illustrates the importance of Design for Manufacturability and Design for Assembly concepts about components of prefabricated systems. In this regard, this research has been carried out to identify the criteria and indicators for selection of prefabricated peripheral walls and to design a system based on updatable databases to select proper options according to the importance of criteria and indicators in various mass housing projects. The research method is descriptive-analytical. The results indicate the necessity of involving building material suppliers in designing the mentioned system. Therefore, it is envisaged to continuously import new material specifications in the form of suggested options by the material suppliers in the system’s database. Peripheral wall selection criteria and indicators extracted from the literature review of prefabrication and an Analytic Hierarchy Process structure is proposed to obtain the appropriate options considering the importance of criteria and indicators. To determine the scoring criteria for options, on the one hand, the standards set for the technical specifications of materials were discussed and on the other hand, examples include materials and Peripheral wall systems based on the prefabrication criteria, were investigated.

The paper presents a methodology for the design of the production process of a new product from the point of view of manufacturability criterion assembly operations (Design for Assembly - DFA) in the automotive industry. Methods and techniques, used in implementation of the DFA method to produce a new product, are mentioned. Impact of those methods on improving the assembly technology of a complex product is described. Suggestions for improving the abovementioned methods are presented, as ell. The examples given illustrate the proposed procedures.

Product variety is a growing trend of offering highly configurable products at the cost of inducing complexity in manufacturing. Joining is a key manufacturing process and historically was a paper-based process with incomplete variety documentation. Nowadays, digital joining element design is a substitution of paper for 3D space. Nonetheless, it remains an ambiguous manual task with limited automation, resulting in time-consuming iterative error-prone development trajectories and costly reworks. This contribution addresses the state of the art in joining element design in both research and industry practice. It reviews product variety and its impact on joining processes. The paper identifies a need for integrating product variety into joining element design and it proposes a solution pathway using artificial intelligence methods.

A new design methodology for long life and large size (Ll-Ls) products called Design for Installation (DfI) is proposed. Ll-Ls products are usually made up of large parts that need to be assembled on field. The proposed methodology, based on adapted Design Structure Matrix (DSM) and Design for Manufacturing and Assembly (DfMA) methods, enables to optimize the design of a Ll-Ls product in order to reduce time and cost of the installation process. The new methodology works with a conceptual design of the product and the weight and size restrictions given by logistic factors as inputs.

The article addresses the redesign of a landing gear for a light aircraft that suffered from manufacturing and assembly problems. Numerical parameters of design features are related to design guidelines for identifying fabrication and assembly issues within 3D model analysis. For this work, the Lucas method of the DFMA integrated with reverse engineering was used as a methodology for the redesign, and its evaluation parameters for resizing the assembly item. Subsequently, the geometry of the redesigned component was defined, where significant reductions were obtained for the evaluation rates of the method used. Reduction from 20 pieces to just 6, which corresponds to a gain of 42% for functional analysis, reductions of 72% for power analysis and 84% for assembly analysis.

Joints design is an essential step in the process of designing timber structures. Complex architectural topologies require thorough planning and scheduling, as it is necessary to consider numerous factors such as structural stability, fabrication capabilities, and ease of assembly. This paper introduces a novel approach to timber joints design that embed both fabrication and assembly considerations within the same model to avoid mistakes that might cause delays and further expenses. We developed a workflow that allows us to identify the fundamental data to describe a given joint geometry, machine-independent fabrication procedures, and the assembly sequence. Based on this, we introduce a comprehensive descriptive language called Joint Descriptive Model (JDM) that leverages industry standards to convert a joint into a usable output for both fabrication and assembly simulations. Finally, we suggest a seed of a joint’s library with some common joints.

Defects generated by the UK supply chain is much higher than its global competitors. Defects impact costs and production throughput due to unpredictable disruptions resulting in many non-value adding activities. However, defects data associated knowledge have rarely been considered and implemented as the manufacturing capability in existing design for manufacturing and assembly (DFMA) data/knowledge bases. On the other hand, current ICT systems used in the aerospace industry are not flexible enough to keep up with the new requirements of collaborating to manage knowledge properly, and the use of real-time manufacturing data generated in manufacturing activities. This research was carried out in collaboration with one of the UK’s largest aerospace companies in order to analyse the complexity of design and manufacturing activities of high-value safety-critical aerospace products. The results of the work are presented, and a novel approach and system was developed, that can be used to support DFMA using defects knowledge. The approach was implemented as a knowledge management system using collaborative design principles. Key findings from the main contribution in the context of extended enterprises of high value low volume safety critical product manufacturing are discussed.

Structuring items for recyclability is driven by ecological and monetary objectives. A few Design for Assembly (DFA) rules and boundaries can be used to check the recyclability plans. These lists can be utilized for near examination of the recyclability of various items. This helps the designers in settling on structure decisions identified with the item's finish of life. In the present research work, the boundaries will be explored from the existing DFA time gauge tables. The aftereffects of the examination showed the recyclability of the item, as characterized by set up recyclability metrics. A contextual analysis is performed to decide whether DFA boundaries could be used to decide product/part recyclability. A TODIM approach is applied to evaluate the recyclability of a tractor’s engine component based on the data obtained from “X” company. Furthermore, TODIM results were examined using MATLAB software. This exploration investigates how designers can utilize the (DFA) boundaries to foresee the recyclability list of an item. The recyclability list will be created utilizing the standards of plan for dismantling and material recyclability. The examination prompted the advancement of a method that an expert could use to decide item recyclability during the reasonable plan period of the fabrication process.

For the past few decades, topology optimization (TO) has been used as a structural design optimization tool. With the passage of time, this kind of usage of TO has been extended to many application fields and branches, thanks to a better understanding of how manufacturing constraints can achieve a practical design solution. In addition, the advent of additive manufacturing and its subsequent advancements have further increased the applications of TO, raising the chance of competitive manufacturing. Design for additive manufacturing has also promoted the adoption of TO as a concept design tool of structural components. Nevertheless, the most frequent applications are related to lightweight design with or without design for assembly. A general approach to integrate TO in concept designs is still missing. This paper aims to close this gap by proposing guidelines to translate design requirements into TO inputs and to include topology and structural concerns at the early stage of design activity. Guidelines have been applied for the concept design of an inner supporting frame of an ancient bronze statue, with several constraints related to different general design requirements, i.e., lightweight design, minimum displacement, and protection of the statue’s structural weak zones to preserve its structural integrity. Starting from the critical analysis of the list of requirements, a set of concepts is defined through the application of TO with different set-ups (loads, boundary conditions, design and non-design space) and ranked by the main requirements. Finally, a validation of the proposed approach is discussed comparing the achieved results with the ones carried out through a standard iterative concept design.

The main goal of this study is to explore the adoption of a design for manufacturing and assembly (DfMA) and building information management (BIM) approach during the whole lifecycle of assets. This approach aims to tackle issues inherent in the design of traditional construction methods, such as low productivity and quality, poor predictability and building performance, and energy use, through the implementation of a BIM library of off-site components. In recent years, a renewed interest has been directed to the attempt to provide solutions to these urgent problems through the adoption of new advancements in technologies. However, while there are studies focussing on a BIM-DfMA approach, there is a lack of research regarding how this approach should be adopted during the whole lifecycle of the assets. Furthermore, to the best of our knowledge, defining an efficient way of developing a component-based BIM object library has not yet been included in any of the available studies. A mixed methodology approach has been used in this research. A conceptual framework was developed as the result of an extensive literature review to investigate new advancements in the AEC sector. Following the literature review, the framework was tested and validated through a case study based on the production and adoption of a BIM library of off-site components at the design stage of an asset. The architecture, engineering, and construction (AEC) industry has recognised the necessity of a new approach that helps to resolve the well-known issues presented in traditional methods of construction. The conceptual framework and case study proposed presents a valuable new method of construction that support the implementation of a BIM and DfMA approach, highlighting their benefits. This framework has been created using many valuable and reliable sources of information. The result of this research supports the idea of a novel new construction method that focuses on a manufacturing-digital-driven industry, with the use of DfMA in a BIM-integrated approach. This novel method will add significance and be beneficial for a wide range of aspects in the construction sector, contributing to the theoretical and practical domain.

Part design is the most important enabler to automate assembly processes. Design work done in companies’ development departments determines most of the product and production costs through material selection and number of components. Part design mostly focuses on functionality but there is still high potential in production processes. To optimize part design for manufacturing and assembly processes first approaches were made between 1960 and 1980. Nowadays, these systematic procedures for optimized component development with respect to production processes are known as ‘Design for Manufacturing and Assembly’ and ‘Design for Automatic Assembly’. Existing part design rules mainly focus on rigid parts. Limp components are avoided in automatic assembly processes, due to limp material characteristics such as strong deformations due to external force or momentum and shape change during manipulation. However, many products, for example automotive wire harnesses, consist of a considerable amount of limp components. A better design for limp components and their joining-partners might be a solution to simplify subsequent automated production processes. The first step therefore is limp component classification. This paper introduces a new scheme of limp component classification oriented towards an abstraction of automated assembly processes. Different limp material characteristics influence several stages of this process. Therefore, relevant limp material characteristics are assigned to the affecting stages. With this classification, the specific challenges in the automated assembly process become clear. This serves as a basis to define challenges for future automated assembly. In addition, the definition of general design rules for limp components concerning automatic assembly becomes feasible. This paper highlights challenges in limp part assembly automation, abstracts automated assembly processes, reviews and discusses first approaches in limp part classification, and introduces a new scheme for limp component classification. The paper concludes with necessary future research based on the proposed limp component classification.

Manufacturing firms are facing the challenge of minimizing variety-induced complexity in assembly systems. One of the effective approaches to complexity management is to reconfigure the assembly system by rearranging its assembly sequence. In order to rearrange an assembly sequence, a design-oriented approach is necessary because assembly is an activity of connecting parts through an interface between them. It means that the assembly sequence in production is restricted by the structure of interface connections in design. In this vein, this paper introduces a new design-oriented approach called interface design approach to complexity management in assembly systems. First, the mechanism of how the structure of interface connections affects assembly system complexity is identified. Then, an interface design framework is proposed for effectively finding an optimal interface structure and its assembly sequence to minimize assembly system complexity. For evaluating the complexity, the operator choice complexity index is adopted and modified for the interface design problem. In the case study, the framework is applied to the interface design problem by using industrial data of a plasma display panel (PDP) family from LG Electronics. The result of the study demonstrates that the assembly system complexity is significantly reduced by the proposed interface design framework.

When designing a product, care must be taken to ensure that the product can be assembled later on at the manufacturing floor. This paper presents a methodology that takes in a CAD design to check its ease of assembly. The proposed methodology can calculate feasibility scores for an assembly step, then use these scores to calculate the optimal sequence of such assembly steps to construct the end product from its loose parts. Two assembly step scoring rules are presented: local and global assembly feasibility. Local assembly feasibility determines the directions in which two subassemblies can move apart an infinitesimally small distance based on contact faces between the subassemblies. Global assembly feasibility considers whether this small distance can be extended to infinity, by checking the overlap of projections of the pair of subassemblies in locally feasible directions. For both of these rules, problems are reduced to previously calculated scores whenever possible, in order to reduce calculation time. These rules are integrated in an algorithm which generates a complete assembly sequence. This assembly sequence is guaranteed to be the global optimum for the given rules. The algorithm successfully generates an assembly sequence for a small example case; the simplification rules reduced the number of local and global assembly feasibility checks by a factor 10 and 6, respectively.

PurposeThis paper aims to present a design methodology to enable product design for ease of assembly. It is corroborated by means of a case study. The methodology is based on standard time data. This enables quick computation of assembly time as well as comparing different design options for ease of assembly.Design/methodology/approachComponent design that is easy to assemble is likely to take less time and vice versa. Assembly time is a function of product design attributes such as geometric shape, weight, center of gravity, type of material, number of fasteners and types of fasteners. The methodology uses standard data to achieve its objective. Numeric scores are developed for each design feature based on the aforementioned design attributes. This enables not only computation of assembly time for a brand new product but also comparison of two or more alternative design configurations from the point of view of ease of assembly.FindingsThe value of the system is corroborated by means of case studies of actual product designs. It is demonstrated that changing any of the underlying design attributes (such as type of fastener used, number of fasteners used, material of the component and component shape) is likely to result in changing the amount of time taken to assemble the product. The scoring system facilitates the quick computation of assembly timeOriginality/valueThe amount of time to assemble a product before the product is ever designed is facilitated by this system. Assembly time is a direct function of product design attributes. Process time is calculated using standard data, specifically, the Methods Time Measurement (MTM) system. This is accomplished by converting design features into time measurement units (TMUs). Assembly cost can then be easily computed by using assembly time as the basis. The computation of assembly time and cost is important inasmuch as its role in influencing productivity. This is of obvious value not only to the designer but the company as a whole.

In automotive body assembly systems, an optimum assembly sequence planning (ASP) not only increases production efficiency and product quality, but also decreases cost and process cycle time. Typically, ASP evaluation approaches are focused on design for assembly criteria, and very few studies have considered the impact of ASP on dimensional accuracy. The major challenges involving quality-driven ASP evaluation can be enumerated into three categories: (1) batch of compliant non-ideal parts to consider real part defects; (2) variation propagation modeling in multi-station assembly (MSA) system in the presence of stochastic manufacturing errors both at product and process levels; and, (3) the development of dimensional quality criteria for quantitative ASP comparisons. This paper proposes a methodology based on the modeling of dimensional errors propagation in MSA with a batch of compliant non-ideal parts to improve product dimensional quality through optimizing ASP and assembly line configuration. It entails three main steps: (i) assembly sequence generation by k-ary assembly operation method for a predetermined assembly line configuration; (ii) variation propagation simulation taking into account a batch of non-ideal parts, station-to-station repositioning errors, and spring-back phenomenon in MSA system; and, (iii) robust optimization of ASP based on developed quality criteria which contains two quantitative indices. The potential benefits of the proposed methodology are successfully demonstrated on automotive front-rail assembly process.

Purpose The purpose of this paper is to apply firework optimization algorithm to optimize multi-matching selective assembly problem with non-normal dimensional distribution. Design/methodology/approach In this paper, a multi-matching selective assembly approach based on discrete fireworks optimization (DFWO) algorithm is proposed to find the optimal combination of mating parts. The approach introduces new operator with the way of 3-opt and also uses a stochastic selection strategy, combines the discrete selective assembly problem with firework optimization algorithm properly and finds the best combination scheme of mating parts with non-normal dimensional distributions through powerful global search capability of the firework optimization algorithm. Findings The effects of different control parameters, including the number of initial fireworks and the coefficient controlling the total number of sparks generated by the fireworks on the evolution performance, are discussed, and a promising higher performance of the proposed selective assembly approach is verified through comparison with other selective assembly methods. Practical implications The best combination of mating parts is realized through the proposed selective assembly approach, and workers can select suitable mating parts under the guidance of the combination to increase the assembly efficiency and reduce the amount of surplus parts. Originality/value A DFWO algorithm is first designed to combine with multi-matching selective assembly method. For the case of an assembly product, the specific mapping rule and key technologies of DFWO algorithm are proposed.

This letter proposes a novel robotic hand design for assembly tasks. The idea is to combine two simple grippers—an inner gripper, which is used for precise alignment, and an outer gripper, which is used for stable holding. Conventional robotic hands require complicated compliant mechanisms or complicated control strategy and force sensing to conduct assemble tasks, which make them costly and difficult to pick and arrange small objects, such as screws or washers. Compared to the conventional hands, the proposed design provides a low-cost solution for aligning, picking up, and arranging various objects by taking advantages of the geometric constraints of the positioning fingers and gravity. It is able to deal with small screws and washers, and eliminate the position errors of cylindrical objects or objects with cylindrical holes. In the experiments, both real-world tasks and quantitative analysis are performed to validate the aligning, picking, and arrangements abilities of the design.

Functional modeling provides a formal approach to early concept development by directly translating customer needs into desired product behavior. By first developing product functionality, the gap between customer needs and product form is lessened. 70–80% of the life-cycle costs of a product are determined by decisions made by designers during the early design stages. Design for assembly (DFA) is a process in which products are designed with ease of assembly in mind. If a product contains fewer parts it will take less time to assemble, thus reducing assembly costs. If functional models can be evaluated based on the three principles of DFA, cost-effective product concepts can be developed earlier in the design stage. Therefore, it is important to estimate the cost-effectiveness of functional models as early as possible. The main goal of this research is to employ the three principles of DFA to evaluate functional models and develop functional modeling guidelines for reducing and integrating functions. We introduce a case study that illustrates how the proposed method works and helps to reduce the number of functions in the assembly process. Conclusions are then discussed and future research is described.

GRIP Exhaust is a small and medium industry which is engaged in manufacturing which produces mufflers. The production system in this company is to apply a production system made to order, where consumers can order exhaust products according to their requests. Designing exhausts according to technical specifications by applying the Design For Assembly (DFA) method and calculating the time required to assemble custom exhaust products into technical specifications by producing products according to user needs. With Design For Assembly (DFA) to make it easier and push time, but still focus on the function of the product itself and pay attention to the safety factor of its performance. custom stainless steel exhaust takes 2 hours to complete, rust-resistant quality, an efficiency value of 1.23, and has higher advantages and attractiveness in the eyes of consumers.

Many companies have been reorganizing from a sequential to an integrated path known as simultaneous engineering, which aims to reduce development time and costs. The main problem during technology and product development is the integration of the design and manufacturing areas in the product development phase. This paper proposes a model to improve the use of simultaneous engineering by integrating project and manufacturing knowledge areas based on concepts of manufacturing readiness level, design for manufacturing and assembly and technology readiness level. Based on a bibliographic review and a preliminary study conducted over 1 year in a multinational metalworking company, a model was proposed as a method to be applied in the early stages of product development. The results show an integration of proposed engineering areas into a product development process, a cost reduction of 20% and a manufacturing investment reduction of 25%.

Welding is a consolidated technology used to manufacture/assemble large products and structures. Currently, welding design issues are tackled downstream of the 3D modeling, lacking concurrent development of design and manufacturing engineering activities. This study aims to define a method to formalize welding knowledge that can be reused as a base for the development of an engineering design platform, applying design for assembly method to assure product manufacturability and welding operations (design for welding (DFW)). The method of ontology (rule-based system) is used to translate tacit knowledge into explicit knowledge, while geometrical feature recognition with parametric modeling is adopted to couple geometrical information with the identification of welding issues. Results show how, within the design phase, manufacturing issues related to the welding operations can be identified and fixed. Two metal structures (a jack adapter of a heavy-duty prop and a lateral frame of a bracket structure) fabricated with arc welding processes were used as case studies and the following benefits were highlighted: (i) anticipation of welding issues related to the product geometry and (ii) reduction of effort and time required for the design review. In conclusion, this research moves forward toward the direction of concurrent engineering, closing the gap between design and manufacturing.

Design activity is the initial step in manufacturing. In smart factory, these activities should be interconnected. The final cost of a product is affected by decisions which are made in these activities. Since 1980, Design for Manufacturing and Assembly (DFMA) approaches has been developed to guide planners to produce products which are easy to fabricate and assemble. Designing products for recyclability is constrained by environmental and economic targets. Numerous Design for Assembly (DFA) laws and parameters can be employed to measure the recyclability index of product designs. Parallel assembly and disassembly techniques using human and robot collaboration can also improve the design quality by choosing the shorter way to completely dismantle the product or to dismantle wear parts. The implementation of these approaches has created a revolution in today’s industry, by many improvements as reduce product cost, shorter time to market, better quality, and few suppliers of standard parts. In this paper, a novel method to parallel dismantle a product is presented. To improve the design quality of the product, a set of assessment metrics were considered as recyclability for reusing aspect, total disassembly time of the product, parallelism aspect, and design efficiency. A comparative example is used to demonstrate the added value of the proposed approach.

The Success with the application of CAD/ CAM/ CNC machine tools are at a faster rate. CAD/ CAM in manufacturing system can be obtained to make sure that the machines and people are utilized to the greatest possible extent. This paper not only gives an approach for CAD/ CAM but also show how CNC is incorporated with the manufacturing system. That is CAD/ CAM with the integration of the Computer with the CNC machine tools. Today, manufacturing Sector like Automobile, Railway, Aircraft Component requires accuracy with the application of CAD/CAM must be interfaced to achieve technology-based improvement in manufacturing and to get successive improvements in productivity and quality. CAD/ CAM interface has also been developed for the development of computer Aided process planning (CAPP) and Design for manufacturing and assembly (DFMA) techniques. These techniques allow the manufacturing function to influence the design process and to ensure that designers are aware of the effects of various design features on the ease of manufacture of a part. In this paper, we concentrate on the issues and challenges incurred in the conversion from manual process to CAD/ CAM for quick response to customers by shortening the product cycle. The success of CAD/ CAM/ CNC systems depends upon the total integration of hardware and software functions in the overall information flow. The industrial productivity must be improved and maintained to meet the challenges of global market.

Apart from job satisfaction, well-designed ergonomic work environment provides physical safety as well as enhance productivity of workers. In manufacturing facilities, workers’ activities during work involve heavy workloads, such as lifting, exerting excessive force, etc. These contributes ergonomic issues and effective countermeasure to improve this is strongly required. This project aims to verify the ergonomic risk of workers and propose an ergonomic design for the manufacturing workstation. Nordic musculoskeletal questionnaire (NMQ) and principle of universal design was used in the existing workstation of partner company. Its simulation model was implemented using (CATIA V5) and digital manufacturing simulation software (DELMIA V5). As a result, computed analysis of Rapid Upper Limb Assessment (RULA) and energy consumption in the workstation were obtained. Results showed that RULA and energy consumption of the proposed design were better than the existing design. Feasibility of the proposed design will be discussed using the results of simulation (177).

The paper provides a method to acquire, process, and represent DfMA rules to help designers and engineers in the development of mechanical products compliant with manufacturing and assembly technology. This research work wants to define a general method able to link DfMA design guidelines (knowledge engineering) with geometrical product features that are available by the investigation of the 3D model. Numerical parameters of design features are related to design guidelines for the identification of manufacturing and assembly issues within the analysis of the 3D model.

Offsite construction (OSC) is attracting increasing attention from both industry and academia due to its benefits, such as improved productivity and quality, as well as reduced waste. However, the current building panelization design in OSC is a time-consuming and experience-based manual process, and the generated panelization design may result in unbalanced manufacturing processes. One reason is that the prefabrication of building components involves a highly variable product mix and there is a lack of a computational framework to evaluate panelization design. The objective of this research is, thus, to propose a BIM-based generative framework that automatically generates the design of production components with the aim of improving production productivity. This framework consists of a building information extraction module, a generative design algorithm, and a simulation-based performance evaluation model. The building information extraction module is designed to extract building component information from a BIM model and classify building components into different production groups in accordance with functionalities and materials. The generative design algorithm is then developed to formulate panelization design alternatives in consideration of the structural, production, and logistics constraints. On this basis, the generated panelization designs are quantitatively assessed by a simulation-based evaluation model in terms of productivity. A case study was used to verify and validate the framework. This research contributes to the body of knowledge by a computational framework of building panelization design, which leverages the generative design algorithm and BIM-simulation integration for optimized panelization design.

Design (DFM) and design for assembly (DFA) are now known as a single process, and in other words, it is called DFMA. The most common methods of DFMA are then studied in the production assembly concept with the features of each block. DFA is a tool used to select the most expensive items and product selection for a variety of product types. The aim of the case study was to arrive to the conclusion or generalized design aspects for the fan design in today’s industrial requirement such as cooling tower where the steel blade fans are being converted to fiber reinforced plastics where we can choose the glass material of varied density and difference combinations can be altered. Also approach of the design for failure mode calculates the priority or necessity of the design aspects and stages of the product design which depicts the time saving, material saving, and cost-effective approach.

The realization of Modular Construction (MC) is impeded by several barriers, e.g., initial investment, logistics constraints, and negative perception. Design, a profoundly creative process to alleviate difficulties in the built environment, is prospected to enhance this construction method. Under this circumstance, many guidelines, recommendations, and avoidances have been proposed to design. However, every coin has two sides. This research, therefore, argues that MC also provides new design opportunities, which have not been yet extensively investigated. It does so by comprehensive literature review and detailed archival study of successful case studies. The result unveils that although MC, by nature, may impose several design limitations, e.g., design simplification, standardization, and limited dimension, it can also serve demands and construct an outstanding architectural design by, for example, a composition of three-dimensional unit, mass customization, and product prototype. This research creates a balanced view of MC in a design process, and highlights the new approach for further design and research development in this discipline.

This study aims to design a semi-automatic assembly line that is relevant to human-robot task allocation problems. It combines two methods, which are Design for Assembly (DFA) and optimization. First, the DFA difficulty score of each task including inspection is evaluated when it is performed by humans and robots. The score is then put in an optimization model. A mathematical model optimally assigns tasks to humans and robots with a feasible sequence. The proposed mathematical models are illustrated on a Lego-car assembly with two demand scenarios, being low and high. Results show that while three single objective models do not provide good solutions, a multi-objective linear problem (MOLP) minimizing a total cost, a cycle time, and difficulty scores altogether provides a better solution. The weights of objectives in MOLP are determined by a modified two-person zero-sum game with a weighted sum method.

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

The evolution of design has come of age and the new design approaches that look at the rapid change and short life cycles of products is taking the centre stage. Competitiveness and the cost of products determine the lifeline of an organisation. The traditional machine tools such as the dedicated and flexible machines are designed on the principle of machine design. The development of reconfigurable machines seeks a new approach to design that not only encompasses the existing approaches but should include new design approaches as well. The success of a designed product maybe measured by the capability of the system that produces it. It is critical when designing a product that the organisation’s technological and manufacturing system capabilities be considered as failure to do so may lead to production designs that are not manufacturable. A good design system ensures quick delivery of a quality, reliable and safe product. This research therefore seeks to develop an integrated approach to design that incorporates design for manufacturing, design for assembly, concurrent engineering, eco-design and reconfigurable design as critical components for reconfigurable machine tool. Literature on these systems was reviewed to integrate the different design paradigms. The results of the study give a new approach to a reconfigurable machine design based on the integration of the five design approaches and their impact in the life cycle of a product.

The paper presents methodology for designing the production process of a new product from the point of view of the assembly operations technology criterion (Design for Assembly - DFA) in the conditions of high-volume production. Mentioned are DFA methods and techniques used in the implementation of a new product. Author presents a new method for assessing design for manufacturability based on fuzzy variables based on fuzzy variables. An example was given to illustrate the proposed course of action

To remain competitive in the market, it is crucial to reduce the time and costs involved in product development. Design for manufacturing and assembly is an engineering methodology that can reduce costs without compromising reliability, performance and time to market objectives. This paper presents a case study for an in-market Table Top Chain (TTC) conveyor system used by a reputed company in Saudi Arabia. TTC conveyor systems are extensively used by major food companies around the world for transporting packaged bottles, glass and cans. There are three main types of these systems, i.e., straight running, side flexing and multiflex. This work focuses on the redesign of a side flexing TTC conveyor system. The existing design of the TTC conveyor system was analysed using the DFMA 9.3 software. The outcomes of the initial analysis were utilised to redesign the TTC conveyor system for cost and design efficiency improvements. The optimum design was selected using Pugh controlled convergence method and further tested for its structural performance using finite element analysis. The redesigned model showed substantial improvements with cost reductions of 29% and an increase in design efficiency from 1.7% to 5%. Finite element analysis has also been carried out with SolidWorks 2019 to validate the structural integrity of the new concept design.

Tolerance allocation is a very important assignment. In fact, knowing how to allocate efficiently tolerances for assembly parts in a computer-aided design (CAD) and computer-aided manufacturing (CAM) system is a very key issue because the cost and quality depend directly on dimension tolerances. The traditional optimization approaches complain about a lack regarding the evaluation of manufacturing difficulty to solve tolerance allocation problem. In this paper, a new approach based on difficulty coefficient evaluation (DCE) and Lagrange multiplier (LM) method is presented to obtain an economical tolerance allocation. In fact, DCE technique, based on the failure mode, effects and criticality analysis (FMECA) tool, is used to quantify the manufacturing difficulty of mechanical parts, as well as the LM method is developed to optimize the proposed approach while respecting the functions and manufacturing requirements. A case study is established to verify the highlights of this work. Indeed, the computed result shows that the method can produce tolerance allocation economically and accurately according to difficulty requirements. Consequently, the proposed method is performed to exploit fully design for manufacturing and assembly (DFMA). For this, an integrated CAD/tolerancing model based on manufacturing difficulty (ICADTMD) is developed using graphical user interface (GUI) in MATLAB.

Timber is gaining its popularity in the construction of low to the mid-rise buildings and sometimes in high-rises due to its sustainability, cost-effectiveness, and availability all around the world. In addition, the prefabricated building is getting popular due to advances in the automation industry, reduction in resources including time, labour, and waste; and cost-effectiveness in mass production. Due to higher capacity demands for mid-rises and convenience in design for manufacturing and assembly (DfMA) in prefabrication, a new development of prefabricated load bearing closed panel composite timber (CPCT) wall system made of oriented strand boards (OSBs) stiffened by sawn-cut timber stud and sometimes with additional steel stud to increase its load carrying capacity has been considered in this research. Five full-scale CPCT walls have been tested subjected to axial compression. The results showed that the mid-height lateral deflection governs the maximum allowable force acting to this wall. Moreover, finite element analysis (FEA) has been done and compared to the experimental results. Once a good agreement between the experimental results and FEA results has been obtained, parametric studies have been performed to comprehensively understand the sensitive parameters affecting the axial behaviour of this system. The parameters studied in this research include the material, the size and the arrangement of the stud, the spacing of the nail, and type of adhesive. Moreover, the possible issue in the practice and the effect of the additional steel stud have also been discussed.

In recent years, remanufacturing has received increased attention as a sustainable and profitable product recovery strategy. To facilitate the remanufacturing of used product returns, factors which affect remanufacturability should be considered during the product design stage. The selection of fastening method during the product design stage is one of the critical decisions which affects the remanufacturability as well as the total cost of disassembly and re-assembly of used products. Hence, both product assembly and disassembly issues should be considered in the product design stage for the selection of fastening methods. Simultaneous consideration of product assembly and disassembly in the product design stage for the fastening method selection has not been properly addressed in previous studies. In this paper, a methodology for selecting appropriate fastening method from a remanufacturing perspective is proposed in which both product assembly and disassembly are addressed. In the proposed methodology, an optimization model is formulated with the objective of minimizing the total cost of product assembly and disassembly. The genetic algorithm is employed to solve the model. A case study on the selection of fastening method for a laptop computer is conducted to illustrate the proposed methodology and to evaluate its effectiveness. The effect of the degree of product disassembly and the demand size for remanufactured products on the total cost of product assembly and disassembly was also investigated. The results showed the proposed methodology provide significant cost savings in the total product assembly and disassembly cost.

Purpose Coordination feature (CF) is the information carrier in dimension and shape transfer process in aircraft manufacturing. The change of its geometric size, shape, position or other attributes would affect the consistency of accumulated errors between two or more assemblies. To identify these “key characteristics” that have a close relationship with the assembly precision, a comprehensive method was developed under digital manufacturing environment, which was based on importance calculation. The multi-hierarchy and multi-station assembly process of aircraft products were also taken into consideration. Design/methodology/approach First, the interaction and evaluation relationship between components at different manufacturing stages was decomposed with a hierarchical net. Second, to meet coordination accuracy requirements, with the integrated application of Taguchi quality loss function, accuracy principal and error correction coefficient H, the quality loss between target features and candidate features at adjacent assembly hierarchies were calculated, which was based on their precision variation. Third, the influence degree and affected degree of the features were calculated with DEMATEL (decision-making trial and evaluation laboratory) method, and the concepts of centrality degree index and cause degree index were proposed for calculating the complete importance degree to eventually identify the CFs. Findings Based on the proposed methodology, CFs, affecting the skin profile and the flush coordination accuracy, were successfully identified at different assembly hierarchies to a certain type of wing flap component. Originality/value Benefit results for the engineering application showed that the deviation of skin profile was more accurate than before, and the tolerance was also closer to the centerline of required assembly precision range. Moreover, the stability in the assembly process was increased by 26.9 per cent, which could bring a higher assembly quality and an enhancement on aircraft’s flight performance.