The DFX shell: A generic framework for developing design for X tools

The Design for X (DFX) shell is a generic framework which can be easily extended or tailored to develop a variety of DFX tools quickly with consistent quality. A number of formal but pragmatic constructs are provided. Bills of materials are used to describe and analyse the overall product structure and product characteristics. Flow process charts are used to describe and analyse the overall process structure and process characteristics in relation to individual product elements. Standard operation process charts are modified to describe and analyse the overall process structure in relation to the product structure. Appropriate performance measures are used to evaluate the interactions between the elements of products, processes and resources. This paper discusses a systematic DFX development procedure. The DFX development procedure consists of seven steps, and each step focuses on a major building block of the DFX shell.     

Web-based product and process data modelling in concurrent “design for X”

This paper is concerned with employing the web technology for concurrent modelling of product and process data on the Internet. This is one of the essential tasks of an attempt to develop a generic web-based Design for X (DFX) shell which can be tailored or extended to develop and apply a variety of DFX tools easily, quickly and consistently. The emphasis is placed on the use of a number of formal but pragmatic constructs. Bills of materials are used to describe and analyse the overall product structure and characteristics. Flow process charts are used to describe and analyse the overall process structure and characteristics. Standard operation process charts are modified to describe and analyse the interactions between the overall product and process structures. These concepts have already been widely used by practitioners or at least are familiar to various personnel involved in product development. They are coded as reusable ActiveX components that can be easily deployed in the DFX shell.     

Geometric skeleton computation enabling concurrent product engineering and assembly sequence planning

This paper introduces a novel modelling approach to geometric skeleton computation enabling concurrent product engineering and assembly sequence planning. Current engineering vision has recently moved towards new modelling and management paradigms to maintain competitive edges all along the product lifecycle. Consistent with concurrent engineering and design for X stakes, this recent shift promotes cross-X and knowledge-intensive philosophies in the product development process, principally focused on lifecycle engineering.The main objective of this research is to integrate assembly process engineering information and knowledge in the early phases of the product development process in a top-down and proactive manner, in order to provide a geometric skeleton-based assembly context for designers. The definition of the product and its related assembly sequence requires both the enhancement and the entire understanding of product relationships between the various product components, and its related assembly rationale. As a consequence, this new modelling approach highlights the need to integrate various stakeholders’ viewpoints involved in the beginning of the product lifecycle. In such a context, earlier work has achieved the early generation of an optimal assembly sequence in the product development process, before the product geometry is completely defined. As a result, previous research has made possible to control and bind the product modelling phase through an assembly oriented product structure.The aim of the proposed approach is to compute and define a geometric skeleton model based on product relational information and the early-defined assembly sequence. The proposed approach–called SKeLeton geometry-based Assembly Context Definition (SKL-ACD)–enables the control of the product modelling phase by introducing skeleton entities consistent with product relationships and assembly sequence planning information. A prototype application within a CAD tool has been developed for aiding geometric skeleton computation and generation. Lastly, an industrial case study is introduced to highlight the feasibility and the relevance of the proposed modelling approach.     

Methods and tools supporting modular process design

Increasing competition in globalising markets requires effective means for development and production planning regarding innovative products. One efficient approach is an integrated product and process design, following the idea of concurrent engineering. Initialising process design at an early stage of product development allows for balancing the product characteristics and the process capabilities. In this connection, the architecture of process planning operations has to reflect the information certainty derived from the development process. At the Laboratory for Machine Tools and Production Engineering (WZL), methods and electronic data processing (EDP) tools for a continuous, product related process design in different planning and optimisation phases have been developed. The procedure and the efficiency of the developed methods and EDP-tools which are designed modularly are illustrated in the following paper.     

Design for manufacture and design for ‘X’: concepts,applications, and perspectives

The implementations of design for assembly and design for manufacture (DFM) led to enormous benefits including simplification of products, reduction of assembly and manufacturing costs, improvement of quality, and reduction of time to market. More recently, environmental concerns required that disassembly and recycling issues should be considered during the design stages. The effort to reduce total life-cycle costs for a product through design innovation is becoming an essential part of the current manufacturing industry. Therefore, researchers begin to focus their attention on design for environment, design for recyclability, design for life-cycle (DFLC), etc. These studies are sometimes referred to as Design for X (DFX). Since the late 1990s, hundreds of papers have been published pertaining to DFX applications in manufacturing. Most of them are widely distributed over many different disciplines and publications. This makes it very difficult for one to locate all the information necessary for the application of DFX in manufacturing. A paper that can help researchers and practitioners applying this emerging technology is highly desirable. The objective of this paper is to present the concepts, applications, and perspectives of ‘DFX’ in manufacturing, thus providing some guidelines and references for future research and implementation.     

Assembly operation process planning by mapping a virtual assembly simulation to real operation

Virtual assembly has been widely used in product development. However, virtual operation and actual operation are different in time and space, the simulation of interactive virtual assembly cannot support the assembly operation's process planning directly. In this paper, the solution for assembly operation's process planning is developed based on interactive virtual assembly. According to the solution, interactive assembly operation is used to obtain the actions of operation sequence. The actions are mapped into the data of a real operation action to obtain real operation actions. Then assembly operation cards can be obtained. To support the assembly operation actions obtained through virtual assembly simulation, a product assembly model is proposed. An operation semantic model is used to replace the geometric constraint model of assembly, which contains several ordered geometric constraints and some engineering restriction conditions. To test the solution and the models, one process planning example of an automobile engine is introduced. The results verified the feasibility and the effectiveness of the methods.     

Preliminary design and manufacturing planning integration using web-based intelligent agents

Software agents have been increasingly used in the product and process development in industry over the past years due to the rapid evolvement of the Internet technology. This paper describes agents for the integration of conceptual design and process planning. Agents provide mechanisms to interact with each other. This mechanism is important since both of those processes involve negotiations for optimization. A set of design and planning software agents has been developed. These agents are used in a computer-based collaborative environment, called a multi-agent platform. The main purpose of developing such a platform is to support product preliminary design, optimize product form and structure, and reduce the manufacturing cost in the early design stage. The agents on the platform have access to a knowledge base that contains design and planning rules. These rules are derived from an analysis of design factors that influence process and resource planning, such as product material, form, shape complexity, features, dimension, tolerance, surface condition, production volume, and production rate. These rules are used by process planning agents to provide process planners with information regarding selecting preliminary manufacturing processes, determining manufacturing resources, and constructing feedback information to product designers. Additionally, the agents communicate with WEB servers, and they are accessible by users through Internet browsers. During performing design and planning tasks, agents access the data pertinent to design and manufacturing processes by the programming interfaces of existing computer-aided design (CAD) and manufacturing system. The agents are supported by a developed prototype agent platform. The agents and the platform enable the information exchange among agents, based on a previously developed integrated design and manufacturing process object model.     

面向并行设计的特征识别与模型重构方法

在分析现有CAD软件以及产品建模方法不足的基础上，引入广义工程语义特征的概念，应用广义特征对象实现面向并行设计的产品广义信息模型的简化表示；提出一种自动特征识别方法，对识别对象进行分类；以截面复杂的回转体特征为例，着重表述了基于基面的特征识别算法；扼要介绍Pro／E软件中的特征结构树，提出面向Pro／E的特征信息三级提取策略与特征信息模型重构原则，并据此开发了DFX原型系统．     

A PDES/STEP-based model and system for concurrent integrated design and assembly planning

Product data exchange and interfacing between different CAD/CAM systems are of great importance to the development of concurrent integrated design environments and computer integrated manufacturing systems. This paper presents a STEP-based method and system for concurrent integrated design and assembly planning. An integrated object model for mechanical systems and assemblies is first defined by a hierarchy of structure, geometry and feature. The structure is represented as a component-connector or joint multi-level graph with both hierarchical functional and assembly relations. These hierarchical relation models are then used for uniformly describing their causal relations both for assembly level and feature based single part level. The generic product assembly model is organized according to STEP, using mostly the entities of integrated resources and partly self-defined entities, which are necessary for design and assembly planning. Based on the generic product assembly model, STEP-based strategies and agent concepts are used for agent-based concurrent integration of design and assembly planning. A prototype system, consisting of a CAD system, a product modeling system, an assembly planning system, and an assembly evaluation system is developed, in which product data can be exchanged between these subsystems. Details about the implementation of the system are addressed. The integrated design and assembly planning system can support the introduction of a new product. The results of assembly planning are feedback to the stage of assembly design to improve on the design. A case study is carried out for assembly-oriented design of a gearbox, to illustrate the proposed approach and to validate the developed system.     

Integrated multi-layer representation and ant colony search for product selective disassembly planning

Selective disassembly plays an important role in product life cycle to meet requirements of the product repairing, reusing and recycling. An efficient disassembly plan is essential to minimize processing time in product maintenance for cost saving. This paper introduces a method for integration of the multi-layer product representation and the optimal search in product selective disassembly planning. The multi-layer representation is based on the product structure formed in product design. The method enables an efficient search for the disassembly sequence. Unlike the existing product representation methods, the multi-layer representation is a dynamic product data model integrated with an ant colony search process for a near optimal solution. Industrial applications have proven the method effectiveness.     

Development of a feature-based and object-oriented concurrent engineering system

Product information modeling is critical to the integration of mechanical CAD/CAM systems and to the implementation of a concurrent engineering system. This paper presents a recent development of a feature-based and object-oriented concurrent engineering system with its focus on a product information modeling technique implemented in the system. The technique was developed to capture product definition data including form features and their spatial relationships and to store them as an object-oriented information model during the design process. The paper also describes the implementation of the information modeling technique and its application to manufacturing process planning in an object-oriented environment.     

基于DFX数据交换机制的ADO静态绑定技术

基于DFX数据交换机制的DAO静态绑定技术，可以大大降低程序员的人工编码量，提高数据库的访问效率。ADO作为一种通用数据访问对象模型，近年来已成为数据访问的一种趋势。该文结合实际开发经验，详细阐述了在ADO中如何利用DFX数据交换机制实现数据库表中字段到数据成员变量之间的自动静态绑定。     

Conception Innovation Design System Based on PDM Framework

The system is based on the globally shared product model conforming to VRML Standard, and uses SmarTeam (PDM) system to integrate and encapsulate CAD, CAE and other application software for product development. The system takes sugarcane harvester? mobile telephone design analysis and evaluation as an example, and utilizes fuzzy evaluation principle to evaluate the design and simulation analysis results for decisions making. The platform provides a collaborative intelligent environment f…     

基于约束的并行工程产品开发过程规划

本文分析了并行工程产品开发过程中约束的特点，探讨了不同类型约束对产品开发过程规划的不同影响，提出了基于设计约束的过程规划原理推理算法，开发过程活动的划分算法和信息预发布点的选取准则；从整个产品生命周期角度，给出了基于约束的产品开发过程规划的方法和步骤。     

A complexity model for sequence planning in mixed-model assembly lines

Sequence planning is an important problem in assembly line design. It is to determine the order of assembly tasks to be performed sequentially. Significant research has been done to find good sequences based on various criteria, such as process time, investment cost, and product quality. This paper discusses the selection of optimal sequences based on complexity induced by product variety in mixed-model assembly line. The complexity was defined as operator choice complexity, which indirectly measures the human performance in making choices, such as selecting parts, tools, fixtures, and assembly procedures in a multi-product, multi-stage, manual assembly environment. The complexity measure and its model for assembly lines have been developed in an earlier paper by the authors. According to the complexity models developed, assembly sequence determines the directions in which complexity flows. Thus proper assembly sequence planning can reduce complexity. However, due to the difficulty of handling the directions of complexity flows in optimization, a transformed network flow model is formulated and solved based on dynamic programming. Methodologies developed in this paper extend the previous work on modeling complexity, and provide solution strategies for assembly sequence planning to minimize complexity.     

Knowledge-based design for assembly in agile manufacturing by using Data Mining methods

Decision making in early production planning phases is typically based on a rough estimation due to lack of a comprehensive, reliable knowledge base. Virtual planning has been prevailed as a method used to evaluate risks and costs before the concrete realization of production processes. The process of product assembly, which yields a high share in total production costs, gets its particular importance. This paper introduces a new approach and its initial implementation for knowledge-based design for assembly in agile manufacturing by using data mining (DM) methods in the field of series production with high variance. The approach adopts the usage of bulk data with old, successful designs in order to extrapolate its scope for assembly processes. Especially linked product and process data allow the innovative usage of DM methods in order to facilitate the front loading in the product development. The concept presents an affordable assistance potential for development of new products variants along the product emergence process (PEP). With this approach an early cost estimation of assembly processes in series production can be conducted using advanced DM methods as shown in an industrial use case. Furthermore, design and planning processes can be supported effectively.     

三维轻量化模型在制造工艺上的应用

由于工艺数据比设计数据更加庞大,同时在产品设计过程使用众多的三维设计软件,工艺如何和三维CAD进行集成,工艺如何基于三维CAD进行加工工艺设计和装配工艺设计,如何利用三维模型的信息完整、可视的独特优势提高工艺编制的质量和效率,并实现产品模型信息的统一,对于数字化制造具有重要意义。文中重点描述使用三维轻量化技术实现工艺设计的原则和应用场景。     

A digital smart product service system and a case study of the mining industry: MSPSS

Mining equipment products and services no longer meet the needs of future development in the mining industry due to high safety and operational risk. The deep integration of the product-service system (PSS) and digitization is required in the mining industry to promote industry transformation and safe and efficient production without changing the traditional operation mode. This paper proposes a smart product-service system for the mining industry (MSPSS) consisting of a smart product subsystem, stakeholders, smart service subsystem, and smart decision-making subsystem. The analytic hierarchy process (AHP) and virtual reality (VR) are used for decision-making, product selection, operation, and maintenance. The smart product subsystem outputs reliable digital products using three stages: digital design, virtual simulation and planning, and virtual debugging. The smart service subsystem is driven by data and digital technology and provides fault diagnosis and online maintenance services for complex mining products. A case study indicates that all stakeholders can participate seamlessly in the design process. The smart product subsystem uses iterative optimization (more than 100 iterations) to obtain the design results interactively. The smart service subsystem provides digitalized services throughout the entire process. Thus, a stable, reliable, and comprehensive product and service solution is provided for complex mining conditions. The output is used to guide the design, debugging, and operation of physical equipment. The MSPSS has higher design quality and efficiency, a shorter design time, and lower design cost (key performance indicator (KPI)) than the traditional design method.     

STEP-NC compliant approach for setup planning problem on multiple fixture pallets

Manufacturing system configuration is a broad problem that involves various topics concerning workpiece, cutters, fixture and machine. This paper presents an approach to solve the setup planning problem on machining centres based on a STEP-NC compliant data structure. The aim of this approach is to shorten the time required for the process planning activity by automating some time-consuming steps without compromising the solution accuracy. In the proposed approach, a CAM software tool is employed to associate the geometric and technological data regarding the product. Using the proposed data structure, a method is proposed for solving the setup planning problem based on mathematical programming. The developed approach has been tested on a real case.