Concurrent Engineering System Research Articles

A model for the assessment of new technology for the manufacturing enterprise

Modern technology plays a key role in the ability of manufacturing enterprises to compete as world class manufacturers. Managers need to make complex decisions regarding applicable technologies in order to gain optimal return on technological investment. A model was developed to assess the impact of manufacturing technology on the productivity and competitiveness of the enterprise. The approach taken by the model is to view the manufacturing enterprise as a manufacturing system in which different dynamic process structures exist. A framework is defined by the hierarchical structure of the enterprise, the business processes and the fundamental business functions. This creates a 3-dimensional space in which the business processes can be mapped. From the relationship between technology and process, the impact of new technology on the enterprise can be projected onto the 3-dimensional framework. Proven world class manufacturing methodologies can be assessed by the model. These typically include automated manufacturing, production management and concurrent engineering systems. Ultimately, the model can be a useful tool for developing or evaluating technology strategies for the enterprise.

Competitive edge and environmentally‐ conscious design through concurrent engineering

The goal of concurrent or simultaneous engineering is to move a product concept based on a market need to a manufactured and marketable product in the shortest possible time and with minimum cost. The concurrent engineering approaches, processes, and systems should find increasing practical applications in the coming years. Several recent technological advances should help expedite this process.

Four Models of Design Definition: Sequential, Design Centered, Concurrent and Dynamic

Most organisations adhere to one form of product definition as the core of their product development process. The dominant design methodology employed is the foundation upon which the process has to be defined. This paper identifies four very different models for design definition: sequential, design centered, concurrent and dynamic. Using case studies from the automotive and aerospace industrial sectors, this paper illustrates the models identified, which appear to be based on the dominant and prevailing drivers of new product introduction for a given company. The sequential model shows the traditional functionally based organisation and explores how the design is developed through the various functions. The design centered model demonstrates the front end fixing of the design through the use of Design for Lifecycle tools and techniques. The concurrent definition model introduces the concept of concurrent engineering and stage gate systems, with the design definition being fixed at various gates in the process. Finally, the dynamic model demonstrates the interaction of the various functional skill groups and shows a radical departure in the way the design information is transferred in complex organisations.

An expert classification system for production system

The proposed system shows a knowledge base system integrating a geometric modeler, a database, and a knowledge base system, which generates group technology codes to retrieve existing similar design models in database, initiate a model, generate a process plan, and store the new model in the database automatically. We also demonstrate the knowledge based system which is one of the powerful tools applied to integration of design and manufacturing, and the system can be integrated with databases and CAD/CAM systems to implement concurrent production engineering system environment.

Integration of design method software for concurrent engineering using axiomatic design

Concurrent engineering can help manufacturing enterprises to achieve shorter time to market, reduced development costs, and high‐quality products. In order to realize the concurrent engineering, a lot of integrations are required according to parallel development technique, such as the integration of the people with different disciplines, the integration of the software of design methods and design data, and so on. This paper discusses the integration of the software of existing design methods for concurrent engineering by using axiomatic design. The results show that a very complicated software system for concurrent engineering becomes simple and consists of 26 modules corresponding to 26 design methods and one main module which contains all the junctional properties at each level. The task of the programmer for the integration becomes clear and is mainly programming for the main module.

Concurrent engineering system for supporting STEP based activity model

STEP (ISO 10303) is becoming the standard in the process industries for electronic information exchange. To help in the integration of STEP based tools, a process plant engineering activity model has been produced by the PISTEP (Process Industries STEP) consortium. The model provides an overview of the main activities and data flows associated within the process plant life cycle. The model is written as a guideline and can be tailored to meet the particular requirements of a project. This paper describes a computer based project management system (Plantool) that is able to handle activity models within a concurrent engineering framework. The system supports the development and change of an activity model whilst a particular project is being undertaken.

Dicast: um sistema inteligente para auxílio ao projeto de peças fundidas

Este artigo aborda a questão da integração das atividades de projeto e manufatura, descrevendo um sistema de engenharia desenvolvido para auxiliar os projetistas na etapa de projeto detalhado de peças fundidas. O projetar é considerado como uma atividade sujeita a restrições, que condicionam a tomada de decisão. Nesse sentido, o processo de projetar uma peça fundida pode ser modelado como um conjunto de variáveis que representam os parâmetros do projeto interconectados por restrições. Quando alguma restrição não é atendida o sistema se encarrega de avisar ao projetista, indicando qual restrição não foi atendida e as causas prováveis do não atendimento.

Simulation of Hot Isostatic Pressing of a powder metal component with an internal core

This paper presents a finite element simulation of the thermomechanical phenomena occurring during Hot Isostatic Pressing (HIP) of a powder metal component which includes a graphite core. The thermomechanical coupling is achieved in a staggered step manner. The staggered step approach considers the coupled thermomechanical response of solids, including nonlinear effects in both the thermal and mechanical analyses. The creep behaviour of the powder material during densification is modelled using the constitutive equations of thermal elasto-viscoplastic type with compressibility. The various mechanical material properties are assumed to be functions of temperature and relative density. The mechanical solution also includes large deformation and strains. The thermal problem includes temperature and relative density dependent specific heat and thermal conductivity. The constitutive equations and relations for thermal characteristics are implemented into the implicit nonlinear finite element code, PALM2D. The simulation of the HIP process of a component with internal core is chosen as an application example. The component, injection molding tool, is produced of a hot isostatically pressed stainless tool steel with an internal cavity which is achieved by inserting a graphite core into the HIP container. To verify the result of the simulation, the geometry of the capsule and the coated core are measured both before and after pressing using a computer controlled measurement machine (CMM). The measured geometry is compared with the simulated final shapes of the container and internal core. A computer-aided concurrent engineering system (CACE) is used for the complete manufacturing process from the design of the component and finite element simulation to the inspection of the final geometry.

Prioritized constraint network representation and processing for concurrent engineering models

Constraint networks are a major approach to knowledge representation in Concurrent Engineering (CE) systems. The networks model various factors in CE as constraints linked by shared variables. Many systems have been developed to assist constraint network processing. While these systems can be useful, the assumption that a solution must simultaneously satisfy all the constraints is often unrealistic and hard to achieve. Proposed in this paper is a Prioritized Constraint Network. A mechanism to propagate priorities is developed, and a new satisfrability definition taking into account the priorities is described. Strength of constraint supporters can be derived from propagated priorities. Several properties useful for investigating PCN's and finding effective solving strategies are developed.

Lessons from the ‘made in Switzerland’ study: What makes a world-class manufacturer?

Many executives are currently striving to develop world-class manufacturing operations to ensure that they remain competitive in increasingly global markets. To do this, they are adopting a range of practices, from organisational changes such as empowerment and teamwork to the use of techniques such as pull production. Their goal is to substantially improve performance: faster cycle times, reduced manufacturing costs and greater customer satisfaction. The question of how far companies have moved towards world-class manufacturing is at the heart of the ‘Made in Switzerland’ project, a major benchmarking study of Swiss manufacturing practice and performance. The study was carried out in 1995 by IMD faculty and researchers working with consultants from IBM Switzerland. It is part of the internationally-based ‘Made in Europe’ project comprising similar studies in the UK, Germany, The Netherlands and Finland. The central hypothesis of the studies is that the adoption of best practice leads to high performance. The objective is to establish a benchmarking database for participating manufacturers around the world. The studies, which are highly structured, examine six areas of manufacturing practice and performance in detail and assess the relationship between them at individual plants. The areas covered in the study are quality, organisation and culture, concurrent engineering, logistics, lean production and manufacturing systems. Plants in each country are grouped according to their position on the practice and performance indices and then studied in order to pinpoint the issues and challenges facing the manufacturers within that group. Less than three per cent of the 800 plants currently on the ‘Made in Europe’ database are considered ‘world-class’. Yet for manufacturers striving to reach this level of performance, this small minority can provide some valuable insights for the way ahead. This article discusses many of the issues raised by the analysis described above, with particular reference to the ‘Made in Switzerland’ study. In the first section, it looks at the key lessons arising from the Swiss study and what insights these can provide for manufacturers, not only in the Swiss market, but across Europe. In the second section, it looks at how the study can be used for benchmarking and provides manufacturers with some general recommendations to help them focus their improvements and move closer to becoming world-class.

Interactive Multimedia for Engineering Education

SUMMARY Our main educational objective is to support the new, multi-faceted, dynamically changing learning experiences that real life imposes on us and on our students. We have to recognize that traditional, mass produced, highly controlled static and rigid educational methods cannot cope with the increased amount of information, knowledge and inferencing requirements of this rapidly changing world. The life cycle of critical design and manufacturing technologies is contracting. Concepts such as time-to-market, total quality management, local design, global manufacture, concurrent or simultaneous engineering, parallel design and manufacturing, intelligent design and intelligent manufacturing systems are widely accepted. These new technologies require multi-skilled and well-educated engineers and managers as well as flexible and feedback-controlled manufacturing technologies, such as cellular manufacture, computer-integrated manufacturing, concurrent engineering and flexible manufacturing system. It is imp...

Simulation of hot isostatic pressing of metal powder components to near net shape

Presents a finite element formulation of hot isostatic pressing (HIP) based on a continuum approach using thermal‐elastoviscoplastic constitutive equations with compressibility. The formulation takes into consideration dependence of the viscoplastic part on the porosity. Also takes into account the thermomechanical response, including nonlinear effects in both the thermal and mechanical analyses. Implements the material model in an implicit finite element code. Presents experimental procedures for evaluating the inelastic behaviour of metal powders during densification and experimental data. Chooses the simulation of the dilatometer measurement of a cylindrical component during HIP and manufacturing simulation of a turbine component to near net shape (NNS) as a demonstrator example. Both components are made of a hot isostatically pressed hot‐working martensitic steel. Compares the result of the simulation in the form of the final geometry of the container with the geometry of a real component produced by HIP. Makes a comparison between the calculated and measured deformations during the HIP process for the cylindrical component. Measures the final geometry of the turbine component by means of a computer controlled measuring machine (CMM). Performs the complete process from design and simulation to geometry verification within a computer‐aided concurrent engineering (CACE) system.

Process capability modelling in an integrated concurrent engineering system — the feature-oriented capability module

In this paper a system module which models cutting process capabilities is presented. A critical review of process capability modelling in Computer Automated Process Planning (CAPP) systems leads to an outline of current limitations. An approach to modelling of machining facilities which addresses these current limitations is then presented. The technologies of Expert Database Systems, Object Oriented and geometric reasoning techniques are used in the approach. The Feature Oriented Capability Module (FOCM) forms part of a Computer Automated Process Planning (CAPP) System within an integrated concurrent engineering system (Simultaneous Engineering Workstation). In the integrated Simultaneous Engineering Workstation (SEW), a Feature-Oriented Computer Aided Design (CAD) system is integrated with the CAPP system. The approach treats CAPP as an optimisation problem and it is the function of FOCM to provide a plan space of feasible manufacturing solutions on which the optimiser will work. There are several advantages to this approach. In particular it means that the global cost of a process plan is considered. This means that rather than just choosing the cheapest process feature-by-feature, the cheapest global plan is generated. In addition, the FOCM approach of finding sets of feasible plans enables related features to be planned easily and for geometric constraints of processes to be considered in planning. The FOCM takes as input a feature-oriented B-rep solid model description of the component to be planned. Various ‘knowledge sources’ contain sets of rules about manufacture of features and these can query a database and a solid modeller to retrieve data about process constraints. This data is used in the selection of feasible manufacturing processes for the CAPP optimiser plan space. The database provides sufficient detail for actual tool and machine facilities in a factory to be described. The solid modeller is used to provide information on the geometric constraints of operations selected from the database. The knowledge sources query the database to get information about the suitability of an operation in cases where potential tool obstruction, thin walls and intersecting features might make an otherwise suitable operation unsuitable. The queries use object-oriented tool models, machine models and error models which contain geometry descriptions as well as data from the detailed database.

MULTI-AGENT PLANNING AND COORDINATION FOR DISTRIBUTED CONCURRENT ENGINEERING

The centralized planning and control that has defined the traditional information processing structure of manufacturing systems is no longer suited to the current rapidly changing manufacturing environment. For efficient use of manufacturing resources and increased flexibility, it is necessary to migrate to a distributed information processing system in which individual entities can work cooperatively towards overall system goals. The next generation of manufacturing systems requires such an information technology framework to integrate the system components and activities into a larger collaborative enterprise. This paper describes a multi-agent approach to concurrent design, manufacturability analysis, process planning, routing and scheduling. A heterogeneous multi-agent concurrent engineering system consisting of multiple feature-based design sub-systems, multiple simulated shop-floor resource groups, a supervisory control interface and the coordination mechanisms for multi-agent cooperation, has been developed. The architecture of this distributed system and the associated implementation issues are discussed.

A Multiagent Architecture for Concurrent Design, Process Planning, Routing, and Scheduling

A concurrent engineering system has been developed using a multiagent architecture to address the issues of design, manufactur ability analysis, incremental process planning, dynamic routing, and scheduling simultaneously The system includes a feature-based intelligent design subsystem for prismatic components, a shop-floor subsystem to represent available resources, and a supervisory control interface to manage the shop-floor resources The evaluation of the system used a simulated shop-floor environment with four production machines for the design of a prismatic component. As the design progressed, manufacturability was evaluated and shop-floor planning was carried out concur rently Valid process plans, routing, and scheduling were generated The system is now being extended to incorporate additional design systems and shop-floor environments

A concurrent engineering system to support flexible automation in furniture production

Concurrent Engineering (CE) is the consideration of the factors associated with the life-cycle of a product during the design phase. CE is important because it is at the design stage that such aspects as product quality and cost are specified. In the case of flexibly automated production CE is especially important since some designs may be difficult or impossible to manufacture using automated equipment. This paper presents an approach to CE systems for flexible automation that uses constraint networks to represent the constraining influences of the automation process. The approach is illustrated by considering furniture production (in particular wood furniture production). Furniture has been selected as an example because of its inherent complexity both in terms of product geometry and in terms of the furniture manufacturing process. CE Systems and constraint networks are reviewed. The background of both CE and automation for furniture is described. The architecture of CESFAM (Concurrent Engineering System for Flexible Automated Manufacturing), a CE system for flexibly automated furniture production is then detailed. Finally, a description of an example CESFAM session is provided. CESFAM is a system that advises designers, product developers and process planners on improvements that can be made to the design so as to improve product quality and manufacturing efficiency. It has a number of operational advantages over other potential approaches. These advantages include the fact that CESFAM allows the designer to take a pro-active part in the design function by giving straightforward advice , in real-time, for design improvement. Additionally, the system is bidirectional in that the designs can be analyzed during initial development or backtracked from a final design concept.

A methodology for analysing large-scale concurrent engineering systems

SUMMARY A key problem in large-scale concurrent engineering systems is the control and management of the large amount of information required. Constraint networks that are used to represent this information can become so large that structural and operational problems are difficult to identify and rectify. This paper proposes a new approach, called Meta-nets, to modelling large-scale concurrent engineering problems. Meta-nets provide an abstraction of an underlying constraint network. The overall result is a compact and powerful representation of the information flow. The abstraction and analysis of Meta-nets gives several important benefits. First, by dealing with network structure based on information flow, Meta-nets can assist in network navigation. Second, Meta-nets give the dependence relationships between variables in the concurrent engineering system. Third, Meta-nets effectively represent parallelism (i.e. the carrying out of activities separately but with some measure of cohesion), which is an ess...

Basic Studies on Computer Aided Concurrent Engineering for Hull Structure Design and Piping Design

It is often said that Concurrent Engineering (CE) is one of the most important technics in various industries today. In this paper, authors indicate methodology of computer aided CE for hull structure design and piping design.Authors have already reported the prototype system for CIM (Computer Integrated Manufacturing). This system is SODAS (System Of Design and Assembling for Shipbuilding). In SODAS, design system for hull structure and design system for piping are integrated. And these systems are integrated by the concept of Product Model. So authors develop the computer aided CE system based on SODAS in this study.Keeping consistency of product information and management of supposed information are important in CE. Relation of product information is very important to keep consistency of product information. So authors define “Constraint Relation Information” and anthors make it possible to generate “Constraint Network” from “Constraint Relation Information”. By using them, keeping consistency of product information and management of supposed information are made possible.

Combining process planning and concurrent engineering to support printed circuit board assembly

Research in computer integrated manufacturing area has long been concentrated in building the bridges between the islands of design and manufacturing. Many computer-aided process planning systems and design advice systems find success in using Expert System technology to connect design and manufacturing. However, the one-directional inference and hierarchical structure of Expert Systems can only provide a one-way bridge from design to manufacturing or from manufacturing to design. This paper uses interactive constraint modeling to provide a two-way bridge between design and manufacturing and describes PACE II, a process planning and concurrent engineering system for printed circuit boards (PCB). Interactive constraint modeling is a formalism that can represent mutually constraining parameters and their relationships as a set of inter-related constraints. It provides omni-directional and interactive inference to act as a two-way bridge between design and manufacturing in order to solve concurrent engineering problems. By using an interactive constraint modeling environment called Jupiter, the PCB process planning knowledge can be represented in PACE II by a collection of variables which are interlinked by constraints that specify relationships among them. The PACE II system demonstrates that by using interactive constraint modeling, the knowledge involved in process planning can not only generate the process plan but can also serve as a design aid to show the impact of design variations on the manufacturing process. It dynamically generates the process plan from PCB design attributes and detects inconsistencies between the PCB design and the existing production environment, thereby helping to ensure that concurrent engineering can be carried out during the design phase.

Implementation of a logic-based support system for concurrent engineering

In this paper we detail the representation and implementation techniques used to build SPARK, a logic-based support system for designers engaged in concurrent engineering. Design rules are represented as constraints in a constraint satisfaction problem. This problem is translated into equivalent order-sorted logic formulae that form a concurrent engineering logic problem. The solution to this problem is determined through interactive constraint satisfaction performed by a deduction system and associated proof strategy. This illustrated with an example from Printed Wiring Board Design.