scholarly journals An Over-View Of The Applications Of Dfa (Design For Assembly) Techniques On Automobile Components For Reducing Assembly Time And Cost

2021 ◽  
Vol 1123 (1) ◽  
pp. 012003
Author(s):  
Shrey Arvind Jaiswal ◽  
Gnanaraj S Darius
Keyword(s):  
Design For Assembly ◽  
Assembly Time ◽  
Automobile Components

Evaluation and Comparison of Two Design for Assembly Methods: Subjectivity of Information Inputs

2011 ◽  
Author(s):  
Eric Owensby ◽  
Aravind Shanthakumar ◽  
Vikrant Rayate ◽  
Essam Namouz ◽  
Joshua D. Summers
Keyword(s):  
Consumer Products ◽  
Bench Mark ◽  
Design For Assembly ◽  
Assembly Time ◽  
Subjective Information ◽  
The Times ◽  
Types Of Information ◽  
Information Amount ◽  
Complexity Algorithm ◽  
Assembly Software

This paper presents a comparison study on two design for assembly (DFA) tools, Boothroyd and Dewhurst’s Design for Manufacturing and Assembly software and the Mathieson-Summers connective-complexity algorithm, focusing on the amount of information required from the designer to complete the analysis and the subjectivity of this information. The Boothroyd Dewhurst software requires the user to answer a set of questions about each part and how it is assembled to estimate an assembly time, assembly cost, and to suggest design improvements. The connective-complexity method predicts assembly times based on the physical connectivity between parts within an assembly. The methods are applied to three consumer products and evaluated and compared through five criteria: approximate time to conduct the analysis, predicted assembly time, amount of required input information, amount of subjective information, and number of redesign features provided to the user. The results show that the DFMA software requires the user to go through eight types of information answering a total of forty nine questions per part. Sixteen of these questions are based on subjective information making the analysis nearly a third subjective. The connectivity method requires only two types of information and a total of five questions per part to complete the analysis, none of it being subjective. The predicted assembly times from the connective-complexity DFA method ranged from 13.11% to 49.71% lower than the times predicted by the DFMA software. The results from this comparison can be used to bench mark DFA methods so that their weaknesses can be identified and improved.

Reduction of Acquisition Time Through New Design for Assembly Heuristics

1994 ◽  
Author(s):  
Robert H. Sturges ◽  
David O. Hunt
Keyword(s):  
Product Design ◽  
Information Flow ◽  
Acquisition Time ◽  
Design For Assembly ◽  
Automatic Processes ◽  
Acquisition Process ◽  
Assembly Time ◽  
New Information ◽  
Component Orientation ◽  
Time Averages

Abstract Rearranging component positions and orientations inside products can reduce the acquisition times associated with handling distance and component orientation. Modeling the acquisition process with an information-based Design for Assembly methodology identifies and quantifies acquisition difficulty for manual and automatic processes. Heuristics based on evaluations of acquisition difficulty guide the relocation and reorientation of components inside the product to reduce assembly time. Since acquisition time averages one third of the total assembly time, significant improvements are shown to be feasible. A new information flow from downstream assembly issues into product design is demonstrated.

scholarly journals Usulan Perbaikan Peracangan Produk Smart Light Menggunakan Metode Design for Assembly Boothroyd-Dewhurst

2018 ◽  
Vol 1 (3) ◽  
Author(s):  
Arief Irfan Syah Tjaja ◽  
Rochmat Puji Astomo ◽  
Rispianda
Keyword(s):  
Design For Assembly ◽  
Assembly Process ◽  
Lamp Product ◽  
Design Efficiency ◽  
Street Lighting ◽  
Good Design ◽  
Assembly Time ◽  
Light Product ◽  
Led Lights ◽  
Design Result

ABSTRACTSmart Lamp product is a street lighting product which developed by PT X with LED lights concept. The design of Smart Light product is found to be slightly violate the terms of good design to the assembly process proposed by Boothroyd-Dewhurst as there is a component with sharp side, too much for using fastener, difficult fastener installation because the component is blocked and so forth. Existing design efficiency of Smart Light product is based on a calculation using the Boothroyd-Dewhurst table is 7.63% with total assembly time for 1149.1 seconds while the proposed design efficiency is 15.52% with total assembly time is 539.84 seconds. The changes of the design result reduction of the estimated product cost from Rp1.831.721, - and the BEP in 1482 products on existing product to Rp1.732.609, - and the BEP in 1283 products on proposed product.Kata kunci: design efficiency, assembly time, estimated cost, break event point (BEP).ABSTRAKProduk Smart Light adalah merupakan sebuah produk lampu penerangan jalan yang dikembangkan oleh PT X dengan konsep lampu LED. Rancangan produk Smart Light ini ternyata tidak sedikit melanggar ketentuan-ketentuan perancangan yang baik untuk proses perakitan yang dikemukakan oleh Boothroyd-Dewhurst seperti terdapat komponen yang memiliki bagian yang tajam, penggunaan fastener yang terlalu banyak, pemasangan fastener yang sulit karena komponen terhalang dan sebagainya. Efisiensi desain existing produk Smart Light ini berdasarkan pada perhitungan menggunakan tabel Boothroyd-Dewhurst adalah 7,63% dengan waktu perakitan total selama 1149,1 detik sedangkan efisiensi desain usulan adalah 15,52% dengan waktu perakitan total selama 539,84 detik. Perubahan rancangan desain mengakibatkan pengurangan pada estimasi biaya produk dari Rp1.831.721,- dan break event point (BEP) pada produk ke 1482 untuk produk existing menjadi Rp1.732.609,- dan BEP pada produk ke 1283 untuk produk usulan..Keywords: efisiensi desain, waktu perakitan, estimasi biaya, break event point

Application of an Information-Based Design for Assembly Theory to Assembly Workstation Design

1993 ◽  
Author(s):  
David O. Hunt ◽  
Robert H. Sturges
Keyword(s):  
Problem Formulation ◽  
Mixed Integer ◽  
Computational Time ◽  
Design For Assembly ◽  
Assembly Time ◽  
Aspect Ratios ◽  
Workstation Design ◽  
Orientation Time ◽  
Np Hard Problem ◽  
Assembly Tasks

Abstract An effective presentation of components at the workstation can have a significant impact in reducing assembly time. Our goal is to reduce the assembly time by optimization of the component presentation. The assembly factors recognized in Design for Assembly theory as relevant to both parts acquisition and assembly workstation layout are recognition, orientation, weight, and handling distance. This study considers a single manual assembler at an assembly station, with the components in rectangular bins of differing sizes and aspect ratios. Ninety degree rotations are allowed for minimizing potential handling distance. The assembly task is modelled with multiple assembly points representing the final location of the components. Components can be preoriented or random in the bins, with preorientation removing the recognition and orientation time penalties. The problem formulation employs Mixed Integer Non-Linear Programming (MINLP), and numerical evidence suggests an np-hard problem. Heuristic methods control computational time to practical levels for realistic assembly tasks. Our results show that numerical optimization of assembly workstation layout can reduce the expected level of difficulty over random or manual workstation design methods.

Identifying Failure Modes and Effects Through Design for Assembly Analysis

2018 ◽  
Author(s):  
Phyo Htet Hein ◽  
Nate Voris ◽  
Jiaying Dai ◽  
Beshoy W. Morkos
Keyword(s):  
Failure Mode ◽  
Failure Modes ◽  
Estimation Method ◽  
Time Estimation ◽  
Handling Time ◽  
Insertion Time ◽  
Design For Assembly ◽  
Assembly Time ◽  
Time Required ◽  
The Ideal

Design for Assembly (DFA) time estimation method developed by G. Boothroyd and P. Dewhurst allows for estimating the assembly time of artifacts based on analysis of component features using handling and insertion tables by an assembler, who is assumed to assemble the artifact one-part-at-a-time. Using the tables, each component is assigned an assembly time which is based on the time required for the assembler to manipulate (handling time) and the time required for it to interface with the rest of the components (insertion time). Using this assembly time and the ideal assembly time (i.e. the absolute time it takes to assemble the artifact, assuming each component takes the ideal time of three seconds to handle and insert), this method allows to calculate the efficiency of a design’s assembly process. Another tool occasionally used in Design for Manufacturing (DFM) is Failure Modes and Effects Analysis (FMEA). FMEA is used to evaluate and document failure modes and their impact on system performance. Each failure mode is ranked based on its severity, occurrence, and detectability scores, and corrective actions that can be taken to control risk items. FMEA scores of components can address the manufacturing operations and how much effort should be put into each specific component. In this paper, the authors attempt to answer the following two research questions (RQs) to determine the relationships between FMEA scores and the DFA assembly time to investigate if part failure’s severity, occurrence, and detectability can be estimated if handling time and insertion time are known. RQ (1): Can DFA metrics (handling time and insertion time) be utilized to estimate Failure Mode and Effects scores (severity, occurrence, and detectability)? RQ (2): How does each response metric relate to predictor metrics (positive, negative, or no relationship)? This is accomplished by performing Boothroyd and Dewhurst’s DFA time estimation and FMEA on select set of simple products. Since DFA metrics are based on combination of designer’s subjectivity and part’s geometric specifications and FMEA scores are based only on designer’s subjectivity, this paper attempts to estimate part failure severity, occurrence, and detectability less subjectively by using the handling time and insertion time. This will also allow for earlier and faster acquisition of potential part failure information for use in design and manufacturing processes.

scholarly journals Chitosan-Based Adhesive: Optimization of Tensile Shear Strength in Dry and Wet Conditions

2021 ◽  
Vol 2 (1) ◽  
pp. 110-120
Author(s):  
Maisa Abdelmoula ◽  
Hajer Ben Hlima ◽  
Frédéric Michalet ◽  
Gérard Bourduche ◽  
Jean-Yves Chavant ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Shear Strength ◽  
Bond Strength ◽  
Water Resistance ◽  
Tensile Shear Strength ◽  
Tensile Shear ◽  
Spread Rate ◽  
Assembly Time ◽  
Deacetylation Degree ◽  
Dry And Wet Conditions

Commercial adhesives present a high bond strength and water resistance, but they are considered non-healthier products. Chitosan can be considered as an interesting biosourced and biodegradable alternative, despite its low water resistance. Here, its wood bonding implementation and its tensile shear strength in dry and wet conditions were investigated depending on its structural characteristics. Firstly, the spread rate, open assembly time, drying pressure, drying temperature, and drying time have been determined for two chitosans of European pine double lap specimens. An adhesive solution spread rate of 1000 g·m−2, an open assembly time of 10 min, and a pressure temperature of 55 °C for 105 min led to a bond strength of 2.82 MPa. Secondly, a comparison between a high molecular weight/low deacetylation degree chitosan and a lower molecular weight/higher deacetylation degree chitosan was conducted. Tests were conducted with beech simple lap specimens in accordance with the implementation conditions and the conditioning treatments in wet and dry environments required for thermoplastic wood adhesive standards used in non-structural applications (EN 204 and EN 205). The results clearly revealed the dependence of adhesive properties and water resistance on the structural features of chitosans (molecular weight and deacetylation degree), explaining the heterogeneity of results published notably in this field.

scholarly journals CONCEPTUAL DESIGN FOR ASSEMBLY IN AEROSPACE INDUSTRY: SENSITIVITY ANALYSIS OF MATHEMATICAL FRAMEWORK AND DESIGN PARAMETERS

2021 ◽  
Vol 1 ◽  
pp. 731-740
Author(s):  
Giovanni Formentini ◽  
Claudio Favi ◽  
Claude Cuiller ◽  
Pierre-Eric Dereux ◽  
Francois Bouissiere ◽  
...  
Keyword(s):  
Sensitivity Analysis ◽  
Conceptual Design ◽  
Design Parameters ◽  
Design For Assembly ◽  
Mathematical Framework ◽  
Commercial Aircraft ◽  
System Architectures ◽  
Complex Engineering ◽  
Aircraft System ◽  
Definition Of

AbstractOne of the most challenging activity in the engineering design process is the definition of a framework (model and parameters) for the characterization of specific processes such as installation and assembly. Aircraft system architectures are complex structures used to understand relation among elements (modules) inside an aircraft and its evaluation is one of the first activity since the conceptual design. The assessment of aircraft architectures, from the assembly perspective, requires parameter identification as well as the definition of the overall analysis framework (i.e., mathematical models, equations).The paper aims at the analysis of a mathematical framework (structure, equations and parameters) developed to assess the fit for assembly performances of aircraft system architectures by the mean of sensitivity analysis (One-Factor-At-Time method). The sensitivity analysis was performed on a complex engineering framework, i.e. the Conceptual Design for Assembly (CDfA) methodology, which is characterized by level, domains and attributes (parameters). A commercial aircraft cabin system was used as a case study to understand the use of different mathematical operators as well as the way to cluster attributes.

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