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Article
Publication date: 1 December 1996

Hubert K. Rampersad

During recent years numerous design for assembly methods have been developed to optimize product design for robotic assembly and hence reduce assembly costs. Various bottlenecks…

1809

Abstract

During recent years numerous design for assembly methods have been developed to optimize product design for robotic assembly and hence reduce assembly costs. Various bottlenecks in product design are, however, still encountered with the widespread application of robotic assembly systems. These are mainly due to a lack of integral insight into the product design variables. Discusses these variables from an integral point of view, by means of a developed assembly model.

Details

Integrated Manufacturing Systems, vol. 7 no. 6
Type: Research Article
ISSN: 0957-6061

Keywords

Article
Publication date: 1 March 1995

Hubert K Rampersad

Examines the conceptual design of robotic assembly systems inconjunction with the analysis and optimization of the product and processdesign. Explains how an integral assembly

Abstract

Examines the conceptual design of robotic assembly systems in conjunction with the analysis and optimization of the product and process design. Explains how an integral assembly model is utilised to study the relationships between assembly variables which play a role in each stage of the design process. Outlines the characteristics and benefits of the concentric design process and explains the total productivity concept. Concludes that the integral assembly model, which underlies the concentric design process, provides the opportunity to store product, process and system data and can therefore be considered as a reference model for product development and process planning as well as for the design and analysis of assembly systems.

Details

Assembly Automation, vol. 15 no. 1
Type: Research Article
ISSN: 0144-5154

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Article
Publication date: 1 March 1995

Manohar Madan, Tom Bramorski and R.P. Sundarraj

The problems involved in assembly of packaged ready‐to‐assemble(RTA) products such as bicycles, furniture, etc., are well known. Someof the factors that contribute to the…

1124

Abstract

The problems involved in assembly of packaged ready‐to‐assemble (RTA) products such as bicycles, furniture, etc., are well known. Some of the factors that contribute to the difficulty in assembly are unclear assembly instructions and poor grouping of parts in packages. Typically, RTA products are packed in one bulky carton with some parts, such as hardware, grouped in a separate package within the carton. As a result, consumers often spend a significant portion of the assembly time on searching for the right part. Through an experimental study we demonstrate that the assembly time can be significantly reduced by forming logical part groups (packages within the carton) according to the sequence of assembly operations. Our result is significant in the context of recent surveys that indicate customer dissatisfaction with the assembly of RTA products.

Details

International Journal of Operations & Production Management, vol. 15 no. 3
Type: Research Article
ISSN: 0144-3577

Keywords

Article
Publication date: 1 December 2000

Albert C.K. Choi and Prasanthi Guda

Assembly is a necessary and important part of any manufacturing process. Computer aided production engineering allows production engineers to create an on‐screen virtual…

1249

Abstract

Assembly is a necessary and important part of any manufacturing process. Computer aided production engineering allows production engineers to create an on‐screen virtual manufacturing environment which graphically displays and simulates actual manufacturing processes. This is an attempt to analyse the assembly process for a computer mouse, using both the Boothroyd and Dewhurst design for assembly (DFA) and Tecnomatix’s Dynamo software package. A mouse designed in Unigraphics has been the product considered and the assembly process has been analysed. Some of the steps involved in the analysis are explained in detail and the observations and results are discussed along with redesign suggestions. These software systems can help identify some of the technical problems that can possibly be encountered in real life production and can effectively be used to guide the design process. Product assembly, analysis and visualization, which are the prime features of the software in use, enable us to improve the design and enhance the features of products at the conception and design stage itself. This can be a critical factor for maintaining a competitive edge in the fast growing industry today.

Details

Assembly Automation, vol. 20 no. 4
Type: Research Article
ISSN: 0144-5154

Keywords

Article
Publication date: 6 April 2012

S.N. Samy and H.A. ElMaraghy

The purpose of this paper is to present methods for assessing and mapping the complexity of products and their assembly. In cases of complexity of assembly it is important to…

1717

Abstract

Purpose

The purpose of this paper is to present methods for assessing and mapping the complexity of products and their assembly. In cases of complexity of assembly it is important to consider and model at the product design stages when only data about individual parts/products and their assembly attributes are known. Assessing the complexity of assembly systems, based on the attributes of their components, is an essential step towards designing them for the least complexity.

Design/methodology/approach

This paper presents a mapping method between the complexity of products and their variants and complexity of the system needed to assemble them. A method has also been developed to assess and compare the complexity of assembly systems based on the characteristics of their physical components for comparison and re‐design to reduce complexity.

Findings

The complexity dependency matrix estimates the average assembly equipment complexity for a certain product based on the interactions between parts handling, insertion and assembly attributes and assembly system functions. An automobile engine piston, domestic appliance drive, car fan motor and a three‐pin electric power plug products were used to demonstrate the application of the developed methodology.

Originality/value

The developed methods can be used by products and assembly systems designers to identify and alleviate major sources of complexity.

Details

Assembly Automation, vol. 32 no. 2
Type: Research Article
ISSN: 0144-5154

Keywords

Article
Publication date: 22 January 2021

Fatemeh Daneshamooz, Parviz Fattahi and Seyed Mohammad Hassan Hosseini

Two-stage production systems including a processing shop and an assembly stage are widely used in various manufacturing industries. These two stages are usually studied…

315

Abstract

Purpose

Two-stage production systems including a processing shop and an assembly stage are widely used in various manufacturing industries. These two stages are usually studied independently which may not lead to ideal results. This paper aims to deal with a two-stage production system including a job shop and an assembly stage.

Design/methodology/approach

Some exact methods are proposed based on branch and bound (B&B) approach to minimize the total completion time of products. As B&B approaches are usually time-consuming, three efficient lower bounds are developed for the problem and variable neighborhood search is used to provide proper upper bound of the solution in each branch. In addition, to create branches and search new nodes, two strategies are applied including the best-first search and the depth-first search (DFS). Another feature of the proposed algorithms is that the search space is reduced by releasing the precedence constraint. In this case, the problem becomes equivalent to a parallel machine scheduling problem, and the redundant branches that do not consider the precedence constraint are removed. Therefore, the number of nodes and computational time are significantly reduced without eliminating the optimal solution.

Findings

Some numerical examples are used to evaluate the performance of the proposed methods. Comparison result to mathematical model (mixed-integer linear programming) validates the performance accuracy and efficiency of the proposed methods. In addition, computational results indicate the superiority of the DFS strategy with regard to CPU time.

Originality/value

Studies about the scheduling problems for two-stage production systems including job shop followed by an assembly stage traditionally present approximate method and metaheuristic algorithms to solve the problem. This is the first study that introduces exact methods based on (B&B) approach.

Details

Kybernetes, vol. 50 no. 12
Type: Research Article
ISSN: 0368-492X

Keywords

Article
Publication date: 2 October 2007

Chi‐haur Wu, Yujun Xie and Swee Mean Mok

Virtual product design has become a key technology in reducing costly design errors that are often difficult to detect manually. In order to evaluate product assembly in a virtual…

Abstract

Purpose

Virtual product design has become a key technology in reducing costly design errors that are often difficult to detect manually. In order to evaluate product assembly in a virtual environment, it is important to link a product's design in CAD with the constrained complexity of assembly operations in CAM so that the design can be evaluated and modified in a virtual environment before production begins. The paper aims to focus on this.

Design/methodology/approach

The proposed virtual system includes the following components: a product assembly coding model, named Open Structured Assembly Coding System (OSACS), that codes part‐mating operations for assembling any two parts in CAM; a rule‐based code extractor that identifies OSACS codes for assembling product from the part‐mating information encoded in Standard for the Exchange of Product Model Data AP‐203 CAD data; and an assembly‐sequence generator that generates a binary assembly‐tree for the designed product coded with OSACS assembly codes, representing assembly operations in CAM for product assembly.

Findings

The proposed system links the design phase in CAD with the manufacturing phase in CAM. Simulation studies were made using CAD Ap‐203 data files from an actual mobile phone housing assembly. A binary assembly‐tree assigned with OSACS assembly codes was generated for assembling the product. The assembling complexity between any two parts was coded with the unique OSACS assembly codes. The final binary assembly tree represents how the product is going to be assembled in CAM with the mating complexity encoded in the assigned OSACS codes.

Research limitations/implications

The advantage of this virtual product assembly system is that a design can be validated first in a virtual environment without building the expensive physical production system. Moreover, additional design iterations can be performed in the same amount of time to improve product quality.

Practical implications

Linking product design in CAD with assembly operations in CAM can help realize significant cost savings by preventing future manufacturing problems. With the proposed virtual system, a company can prevent a potential problematic design from reaching production.

Originality/value

This paper introduces the conceptual design of a virtual system that links product design in CAD with assembly operations in CAM. This system provides a designer with a virtual product assembly process to evaluate a designed product.

Details

Assembly Automation, vol. 27 no. 4
Type: Research Article
ISSN: 0144-5154

Keywords

Article
Publication date: 5 June 2017

Narges Asadi, Mats Jackson and Anders Fundin

The recent shift towards accommodating flexibility in manufacturing companies and the complexity resulting from product variety highlight the significance of flexible assembly

Abstract

Purpose

The recent shift towards accommodating flexibility in manufacturing companies and the complexity resulting from product variety highlight the significance of flexible assembly systems and designing products for them. The purpose of this paper is to provide insight into the requirements of a flexible assembly system for product design from the assembly system’s standpoint.

Design/methodology/approach

To fulfil the purpose of the paper, a literature review and a case study were performed. The case study was conducted with an interactive research approach in a global market leader company within the heavy vehicle manufacturing industry.

Findings

The findings indicate that common assembly sequence, similar assembly interfaces, and common parts are the main requirements of a flexible assembly system for product design which reduce complexity and facilitate various flexibility dimensions. Accordingly, a model is proposed to broaden the understanding of these requirements from the assembly system’s standpoint.

Research limitations/implications

This study contributes to the overlapping research area of flexible assembly systems and product design.

Practical implications

The proposed model is largely based on practical data and clarifies the role of product design in facilitating flexibility in an assembly system. It can be used by assembly managers, assembly engineers, and product designers.

Originality/value

The key originality of this paper compared to the previous studies lies in presenting a novel assembly-oriented design model. The model enhances understanding of a flexible assembly system’s requirements for product design with regard to reducing complexity and managing variation in a flexible assembly system. These requirements can be applied to product design across various product families within a company’s product portfolio.

Details

Journal of Manufacturing Technology Management, vol. 28 no. 5
Type: Research Article
ISSN: 1741-038X

Keywords

Article
Publication date: 26 September 2019

Anoop Desai

This 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…

Abstract

Purpose

This 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/approach

Component 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.

Findings

The 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 time

Originality/value

The 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.

Details

Assembly Automation, vol. 39 no. 5
Type: Research Article
ISSN: 0144-5154

Keywords

Article
Publication date: 23 November 2021

Md Helal Miah, Jianhua Zhang and Dharmahinder Singh Chand

This paper aims to illustrate the tolerance optimization method based on the assembly accuracy constrain, precession constrain and the cost of production of the assembly product.

Abstract

Purpose

This paper aims to illustrate the tolerance optimization method based on the assembly accuracy constrain, precession constrain and the cost of production of the assembly product.

Design/methodology/approach

A tolerance optimization method is an excellent way to perform product assembly performance. The tolerance optimization method is adapted to the process analysis of the hatch and skin of an aircraft. In this paper, the tolerance optimization techniques are applied to the tolerance allocation for step difference analysis (example: step difference between aircraft cabin door and fuselage outer skin). First, a mathematical model is described to understand the relationship between manufacturing cost and tolerance cost. Second, the penalty function method is applied to form a new equation for tolerance optimization. Finally, MATLAB software is used to calculate 170 loops iteration to understand the efficiency of the new equation for tolerance optimization.

Findings

The tolerance optimization method is based on the assembly accuracy constrain, machinery constrain and the cost of production of the assembly product. The main finding of this paper is the lowest assembly and lowest production costs that met the product tolerance specification.

Research limitations/implications

This paper illustrated an efficient method of tolerance allocation for products assembly. After 170 loops iterations, it founds that the results very close to the original required tolerance. But it can easily say that the different number of loops iterations may have a different result. But optimization result must be approximate to the original tolerance requirements.

Practical implications

It is evident from Table 4 that the tolerance of the closed loop is 1.3999 after the tolerance distribution is completed, which is less than and very close to the original tolerance of 1.40; the machining precision constraint of the outer skin of the cabin door and the fuselage is satisfied, and the assembly precision constraint of the closed loop is satisfied.

Originality/value

The research may support further research studies to minimize cost tolerance allocation using tolerance cost optimization techniques, which must meet the given constrain accuracy for assembly products.

Details

Aircraft Engineering and Aerospace Technology, vol. 94 no. 3
Type: Research Article
ISSN: 1748-8842

Keywords

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