Collaborative Product Assembly Design and Assembly Planning

Methodologies and Applications

C. Lu, J Y H Fuh, Y S Wong

• Publisher: Woodhead Publishing
• Year: 2011
• ISBN:
  9780857093882
• Topic: Business
• Subtopic: Operations
• Index: Business

Collaborative product assembly design and assembly planning presents several newly-developed methodologies and applications for collaborative assembly design and assembly planning, two important steps during the product development life cycle. These benefits include effective and rapid assembly design and assembly planning, thereby reducing the development cost and helping manufacturers enhance profit. With increased development in computer technologies and the Internet, the traditional assembly design and assembly planning have evolved around collaborative assembly design and assembly planning to speed up the product development process. Research in this area has attracted much attention in the past decade. Based on research work in the past few years, this book will present several newly-developed methodologies and applications for collaborative assembly design and assembly planning to improve the efficiency of product development in a collaborative design environment.

• Provides practical and realistic solutions to engineering problems
• Methodologies introduced will lead to future commercialisation of systems
• Detailed step-by-step case study examples will illustrate the methodologies and be discussed thoroughly

Introduction

Abstract:

This chapter discusses the background of the research in collaborative assembly design and assembly planning, the important research issues in collaborative assembly design and collaborative assembly planning are discussed, respectively, and the organization of the book is given.

Key words

background

research issues

organization

collaborative assembly design

collaborative assembly planning.gala

1.1 Background

Product assembly design and assembly planning are two important steps during product development. Assembly design requires designers to design a product which can be assembled more easily and faster, and assembly planning focuses on deriving a feasible and optimal product assembly sequence based on the product’s assembly design, to save assembly cost and shorten assembly time, and the assembly planning results can also be used by the designer to evaluate the product assembly design at the design stage. So, assembly design and assembly planning are two interactive product development processes in the product development cycle, which can comprise a key approach to Design for Assembly (DFA) in Concurrent Engineering.

As product assembly takes a large part of the product development cost, especially for the complex product such as the automobile, machine tool, etc., effective and rapid assembly design and assembly planning can shorten the product development life cycle, reduce the development cost, and thereby help manufacturers to enhance profit.

With the development of the Internet and computer technology, the traditional assembly design and assembly planning have evolved to collaborative assembly design and assembly planning in an Internet-enabled working environment, to speed up the product development process. Therefore, research to facilitate and realize collaborative assembly design and assembly planning in an Internet-enabled environment has attracted much attention. In the following sections, the key issues in collaborative assembly design and assembly planning respectively will be discussed.

1.2 Key issues in collaborative assembly design

Assembly design is an important step in product design, as it enables designers to provide a complete concept of a product that usually consists of many different components. Generally, in traditional computer-aided assembly design, each part is designed in a standalone computer system and then assembled into a sub-assembly or a more complex assembly by an individual or a group of designers in the same location. With the advancement of the Internet and communication technologies, more and more products are designed and manufactured in different locations to meet fast-changing market requirements. Rezayat (2000) reported that about 50–80 percent of the components in a product from Original Equipment Manufacturers (OEMs) are outsourced to external, geographically dispersed suppliers. Hence, products are usually divided into several sub-assemblies or even more detailed parts, and are assigned to multiple designers located in different sites. These designers can design and assemble the parts collaboratively and synchronously through the Internet to speed up the design process, as shown in Figure 1.1.

Figure 1.1 Collaborative assembly design

In collaborative assembly design, usually the following four consecutive steps should occur: first, each designer in a different location designs the parts assigned to him or her according to the design requirements; secondly, the designers assemble these parts into a sub-assembly or more complex assembly product collaboratively through the Internet; thirdly, when one designer modifies a part, the modification should be propagated to the associated parts designed by other designers located in other sites to maintain the validity and consistency of the whole assembly; finally, when the modification of all of the affected parts is completed, a new assembly product will be re-assembled collaboratively.

From the above-mentioned four steps in collaborative assembly design, the first step is basically the same as the computer-aided design in a standalone computer system, while the second and the fourth steps are mainly the geometric assembly modeling functions but realized in a collaborative design environment. However, the third step is quite different from traditional computer-aided assembly design. In a collaborative design environment, when each designer finishes designing his or her parts according to the initial design requirements, those parts should be assembled together correctly. However, if a designer modifies the design after the assembly process is finished, he or she may not know how the modification can affect the other parts developed by other designers because the whole assembly relationship with other associated parts may not be completely known to him or her, and neither are the geometric shape and dimension of the affected parts designed by others. So, it is unavoidable that some conflicts arise during the co-assembly design process. In the product assembly design process, especially for a complex product, design modification should occur frequently when considering downstream manufacturing issues, such as product assemblability, assembly cost, etc.

Therefore, a methodology to support effective design modification in collaborative assembly design is an important research issue.

1.3 Key issues in collaborative assembly planning

Assembly planning is another important step during product development. The objective of assembly planning is to find a feasible assembly sequence with the minimum assembly cost and assembly time. Because assembly costs account for 10–30 percent of total industrial product labor costs (Nevis and Whitney, 1980) and as much as 50 percent of the product manufacturing costs (Rembold et al., 1985), effective assembly planning can significantly reduce the product development cost, and thereby improve the profit margin.

Besides the above, effective assembly planning at the design stage can make the assembly design more practical when considering the detailed assembly process of the product. The assembly planning results, which represent the feasibility and difficulty of the product assembly process and the assembly cost, can provide appropriate decision support to the designers, and help them to identify the design problems and make the appropriate design modification or redesign in the early design stage. Therefore the product development lead time can be greatly shortened.

Due to the importance of assembly planning, it has attracted much research attention in recent years. In order to improve the efficiency of assembly planning, traditional assembly planning using a graph-based approach has evolved into approaches using artificial intelligence, such as genetic algorithm (GA), and the working mode has evolved from single-user assembly planning to multiuser collaborative assembly planning to speed up the assembly planning process. In the assembly planning area, the following research issues are very important and need to be addressed:

How to evaluate the product assemblability in different assembly sequences?

How to derive more effective solutions for the decision maker considering different assembly conditions?

How to evaluate the assembly design from the assembly planning results?

How to realize the collaborative assembly planning effectively?

The above research can further facilitate the efficiency of assembly planning.

1.4 Organization of the book

Chapter 2 is a systematic literature review of the previous works on assembly design and assembly pl...

Table of contents

• Cover image
• Title page
• Table of Contents
• Copyright
• List of figures, tables and lists
• Acknowledgements
• Preface
• About the authors
• Chapter 1: Introduction
• Chapter 2: Literature survey
• Chapter 3: Collaborative assembly design
• Chapter 4: Evaluation of product assemblability in different assembly sequences
• Chapter 5: Advanced assembly planning approach using a multi-objective genetic algorithm
• Chapter 6: Evaluation of assembly design from assembly planning redesign
• Chapter 7: Collaborative assembly planning
• Chapter 8: Conclusions and recommendations
• Index