This projects aims to develop design automation in product development. Design automation causes increase in producibility and decrease in product cost and manufacturing lead time.

The study at hand is proposed to provide a new method and to introduce procedure to the design of wiring pattern for a car seat heater for Kongsberg Automotive, KA. KA is a Norwegian company and a global provider of engineering, design, and manufacture for seat comfort, driver and motion control systems, fluid assemblies, and industrial driver interface products. The method that currently is used in the company to create a wiring pattern is neither sufficient enough nor automated.

In order to design the wiring pattern, at first procedure is handled by the designer. Secondly, car seat heater 2D layout is imported and then, the dimensions of the elements are defined as constraints. Then VBA codes are opened and the program is run. The result will be a wiring pattern in different 2D layouts. To make the design process easier, we have modeled five different layouts; wiring pattern of one element, two elements, three elements, five elements (with two back sides) and one element trapezoidal 2D layout.

The algorithm written in VBA (Visual basic for application) creates the pattern according to the dimensions of the elements which are used as inputs to define constrained parameters. The created macros are simple to use and easy to modify, independent from the programming knowledge. The user is only responsible with parameter input and running the program. The solution gives wiring pattern for a car seat heater.

Quality of the castings is affected by several factors which the designer should take into consideration during the product development process. Although residual stress is one of those, it is often not considered in practical computations. Hence residual stresses are one of the forgotten areas in designing of machine parts. This master thesis is focused on the investigation of residual stresses in a high pressure die casted component, with the aim of extending its service life, by taking results from the study as a feedback.

The investigation of residual stresses was done on a variety of specimens, cast aluminum flywheel, provided by Husqvarna AB. This flywheel is a component in a product of the same company.In evaluating the residual stresses in the part, two tools-simulation and physical measurement were used. Moreover, comparison with these two methods is also done at an area of interest on the flywheel. The simulation was carried out by using MAGMAhpdc-a module for high pressure die casting process, from the commercial software package MAGMAsoft; while for the physical measurements, the hole drilling method was used, a method believed to be less accurate at low stresses areas.

The findings obtained from this study show that the results from both procedures are close, with small deviations observed, which reveals the reliability of the hole drilling method even when the stress levels are low. It is also found that the compressive residual stresses dominate in the component-a preferred phenomenon with regards to residual stress.

The demand for customised products that meet different markets and different customers is steadily increasing. Also, the demand for shorter lead times for the delivery of these customised products puts strains on design departments whose work tends to become increasingly repetitive. At the same time, designing variants takes time from innovative, original design, and/or problem-solving tasks. A powerful tool in the endeavour to cut lead times, workloads, and ultimately costs in order to become more competitive in an increasingly globalised market is Design Automation. Automating tedious and repetitive design tasks will free the designers to focus on the tasks that require skill, creativity, intuition, and cooperation to be solved. Consequently, seeing a need for design automation systems is not difficult. What becomes a lot more difficult is identifying the type, scope, and format of the system implementation, as well as the actual design tasks and activities to support or automate. Therefore, there is a need for structured and systematic approaches for the realisation and implementation of design automation systems. This research work is aimed at presenting such approaches, methods, and aids. It also addresses the importance of identifying the exact tasks to be automated. This has to be done in order to find the method and implementations best suited for solving the tasks, something that is especially important for companies whose human and financial resources might not allow them to invest in a system with functionality that vastly exceeds their actual needs.

The contribution of this work is a structured method for planning for design automation implementation. First, the design process is discussed from an automation perspective. Following this is a presentation of a framework of design automation. This framework has the purpose of serving as a common base for consensual discussions about design automation. In addition, it supports the setting-up of system specifications. The framework is followed by the introduction of a set of identifiers of system needs and potentials, focusing on the existing processes that need to be broken down and identified in order to specify the tasks to be automated. Following this is a set of criteria of system characteristics, focusing on properties of the intended system implementation. Finally, some realisation and implementation issues are addressed and exemplified through a number of pilot system implementations.

The presented method for planning design automation, together with the presented framework of design automation, provides implementers with issues to address regarding potential, need, scope, and format of system implementations. Further, it supports the weighing of desired system characteristics in order to find the right balance between system complexity and functionality.

Design automation can be a powerful tool in the continuous endeavour to cut lead times, workloads, and, ultimately, costs in order to become more competitive in an increasingly globalised market. Identifying a need for design automation is, consequently, not difficult. What becomes a lot more difficult is identifying the actual need, i.e. the type, scope, and format of the system implementation, as well as the actual design tasks and activities to be automated.

There is currently a need for structured and systematic approaches for the realisation and implementation of design automation systems. This research work is aimed at identifying such approaches, methods, and aids. It also addresses the importance of identifying the exact tasks that are to be automated. This has to be done in order to find the tools and implementations that are best suited for solving the tasks, something that is especially important for companies whose resources and economy might not allow them to invest in a system with functionality that vastly exceeds their actual needs.

In this work, the design process is discussed from an automation perspective. Following this is a presentation of a framework of design automation. This framework has the purpose of serving as a common base for discussions about design automation as well as support in the setting up of initial system specifications. This is followed by the introduction of a set of criteria of design system characteristics, to be used for planning for design automation. These criteria, and descriptions of their use for system implementation and evaluation, constitute the main results of this work. The contribution of the set of criteria is a systematic approach to identifying design automation needs and setting up final system specifications. It provides implementers with general questions to answer about potential, need, scope, and format of system implementations. Further, it leads to weighing desired system characteristics in order to find the right balance between system complexity and functionality. Finally, some realisation and implementation issues are addressed. The set of criteria is complemented by guidelines for system implementation supporting some of the criteria.

A design automation system based on the presented criteria and design automation framework is also presented. This system is evaluated by its users who give their views of systems performance related to the criteria’s level of fulfilment.

The main conclusion of this work is that the set of criteria is a powerful tool for planning and evaluating design automation systems. Together with the presented framework, they also provide a structured and systematic approach to identifying the actual needs of design automation and setting up system specifications.

In order to make the designing of product variants more effective and efficient by automating the process, there is a need to break down and analyse the design process. In doing so, a clearer picture of the actual process will emerge. From this, a problem definition and a system specification can be outlined. This paper presents one such case of breaking down a design problem, defining its process character and capturing its inherent domain knowledge. This is then mapped to suitable tools and computer implementations. One of the tools chosen in this work, Case Based Reasoning, is further addressed, together with some implementation issues concerning CBR. Finally, advantages of a variant design approach to setting up CBR indexing templates are presented.

In order to make the designing of product variants more efficient and effective there often exists the possibility of automating the process, or at least implementing some form of computer support to aid the designers. Designing though, is often not a simple and single task. Instead, it often consists of several interlinked sub-tasks that have to be performed either in some previously known order, iteratively, or perhaps even by inference. Furthermore, the levels of knowledge and task formalisation and process maturity may vary from known and clearly documented tasks (explicit), to known but undocumented tasks (implicit), or even unclear and unstructured tasks (ad-hoc).

In doing so a clearer picture of the actual design process will emerge and a problem definition and/or system specification can be outlined [Cederfeldt 2005]. This will in turn give rise to new questions that needs to be answered in parallel with setting up of a final system specification. Some of these questions address the choice of solution approach related to the design process and its inherent knowledge. This paper presents one such attempt at breaking down a design problem, defining its process character and capturing its inherent domain knowledge. This is then mapped to suitable tools, and computer implementations. One of the tools chosen in this work, Cased Based Reasoning (CBR), will be addressed further and some implementation issues of CBR as well as the advantages of a variant design approach to setting up of CBR indexing templates are discussed in more detail.

When creating a design automation system for a mature product, there already exists a complete and functional product design, and the task is to retrace the initial design process to find the input parameters, algorithms, rules, relations and solution strategies (design process information) that govern this initial design.

This paper presents strategies and procedures for retracing, naming, classifying and storing the design process information governing the design variables of a mature product design, seen from a CAD representation perspective. Emphasis is on the strategy for storing the design process information for use with the CAD representation, as well as system transparency and efficient reuse of the documented and stored information.

To ensure and improve the competitiveness of SMEs acting in an environment of distributed engineering and globalisation, four important factors are low cost, short lead-time, improved product performance, and the possibility to adapt products to different costumer specifications. One way of gaining these competitive advantages is to adopt an approach where products are based on prepared design. If some of the work related to these products and design tasks are automated, the design process can become more effective and efficient. This allows for shortened lead-time of product designs, cost estimates (Elgh and Sunnersjö, 2003), more optimised product designs, and customer tailoring, while giving the designers more time for creative problem solving. Companies have to consider the advantages of design automation, its realisation and implementation, as well as its applicability. Other issues of importance are: scope of implementation, how far to push the automation level, procedure for development, identification of information needed, definition of information models (Elgh, 2004), strategy and procedure for handling and storing design process information (Cederfeldt, 2004), selection of suitable application software (Amen et al, 1999), initial cost, maintenance cost, and the use of internal and external expertise. To support companies in choosing appropriate type and level of design automation, there is a need to address the important questions about potential, wishes, requirements, constraints and actual need of design automation. This paper addresses these questions from a SME standpoint. Other issues addressed are the current state of design automation in industry and the companies’ views regarding some important aspects and criteria of design automation characteristics, realisation and implementation.

With the advent of commercial solid modelling systems some fifteen years ago, the opportunity for three-dimensional parametric geometry was opened to industry. Today solid modelling systems are the dominating CAD tool among advanced engineering companies, but despite the time and money saving implications, industry has been slow to exploit the parametric capabilities of these systems (Amen and Sunnersjö, 1996).

One reason for the slow adoption of parametric modelling is that originally many solid modellers suffered from lack of stability under parametric changes. This situation is now changed and if a model in a modern CAD system collapses, this is usually due to modelling deficiencies rather than numerical failures. Straightforward dimensional variations rarely cause any problems. However, to fully exploit the parametric capability for complex features with a variable topology, there is a need for a systematic approach to build stable and purposeful parametric models.

The purpose of this work is to discuss how different modelling approaches relate to the ease of use and robustness of the CAD model in terms of creating variants and product families. We use the term Design for Variability, DFV, for a modelling approach that ensures that parametric models are well suited for variation design.

Cost is one of the most important criteria for the evaluation of product variants. In this paper, a framework for building systems for cost evaluation of product variants and fabrication plants is presented and discussed. These systems have the purpose of governing the design work towards solutions having an optimal balance between product and production properties. The starting point of the proposed procedure is the cost structure of a manufactured product: the identification of information needed for the evaluation of different product variants, fabrication plants, or both; where the necessary information can be derived from; and how information accessibility and extraction can be supported. The creation of information models for product cost, plant resources, process plans and product geometry is introduced, and the relationships between models are examined, supporting system development. Important guidelines for the creation of a parametric solid model that will serve as the foundation for an automated cost evaluation system are presented.

The estimation of product cost is a central activity in the design process. Most companies act in an environment of high competition where the market sets the product price. This, in combination with a focus on satisfying the shareholders’ demand for return on investment, results in a focus on cost as a constraint. Hence, cost is one of the most fundamental criteria for the evaluation of design proposals (French, 1999). However, the manufacturing cost is often calculated late in the product development process when most details are fixed. This means that cost information feedback often arrives too late to be taken into account. That feedback could otherwise have guided the design towards cost-effective, easily produced solutions. Cost estimation is also commonly a task separated from product design and performed by cost accountants. This work distribution requires resources and can be afflicted with loss of information, leading to low quality in the estimations. This subdivision is also not efficient in the search for the best solution, where a number of variant designs are to be evaluated and compared in a short time. When different courses of action are to be evaluated, small changes in customer requirements, product design and production properties have to be handled with caution. Even seemingly small changes can result in undesired effects, such as: low level of conformability with the production system, highly increased cost, and extended manufacturing lead-time.

The fact that application software is getting more and more adaptable enlarges the possibility of in-house-developed cost estimation systems that can be used as a means for enhanced producibility. This calls for systematic methods for system development that ensure system functionality, quality and longevity.

This work has resulted in a framework supporting the development of automated systems encompassing the entire workflow: the design of the product variant, the process planning, the cost estimation, the analysis of the effects on the producibility metrics and, finally, the selection of the most favourable course of action. The framework consists of: the procedure for system development, the definition of information models, the clarification of the relations between information models, the guidelines for parametric solid models, and the means for automated process planning and cost estimation.

The framework has been used when implementing an industry demonstrator. The system can act as a means for enhanced producibility. Different product, production and cost aspects can be studied through the use of multi-objective optimisations, sensitivity analysis, and what-if scenarios enabled by the system. The system can serve as a decisions tool that enables the evaluation of different courses of action in the early stages in the development of product variants. This can imply better decisions and, in the long run, a better company understanding and awareness of the relationships between the product properties, the manufacturing resources requirements/constraints, the manufacturing processing, the cost structure, and the cost level.

For many products, the adaptation to customer specifications is essential and requires flexible product design and manufacture while maintaining competitive pricing. Engineering design is often concerned with striking a good balance between product properties, e.g. performance, and the resources required to manufacture and assemble the product. When different courses of action are to be evaluated, even seemingly small changes in customer requirements, product design, and manufacturing properties have to be handled with caution. Small changes can entail products with: low level of conformability with the manufacturing system, highly increased cost, and extended manufacturing lead-time. For most companies, the manufacturing system is a valuable asset that is more or less fixed and only minor adaptations are allowed. This implies that the product design has to be adapted to the manufacturing system to a large extent.

Design for producibility (DFP) is the process in which a systematic method is used to reach the required functional properties of the product at the same time as good compliance with the manufacturing system is ensured. The DFP process usually needs to involve several persons simultaneously for the purpose of sharing information and knowledge. For many manufacturing companies, the collaboration between engineering design and production engineering is a critical issue and they have to improve their methods and tools for ensuring and enhancing producibility. This can be achieved by introducing computer-supported design for producibility. The present research is intended to contribute to the development and utilisation of different application systems that can be used as such computer support. The aim is to provide companies with support in application system development and to show how different application systems can be used in a systematic way as means to ensure and enhance producibility.

The competitive advantages to gain from introducing computer-supported design for producibility are: product designs with high level of conformability with the production system, shortened manufacturing lead-time, and decreased manufacturing cost. This work contributes to the achievement of these advantages by introducing a framework with principles and models supporting application systems development. Three types of application systems are presented and their practical usefulness is examined, showing practitioners how producibility aspects can be assessed systematically. The main scientific and theoretical contribution of the work comprises: the descriptions concerning how to structure and describe the product and product-related information (manufacturing requirements, costs, process plans and production resources), the foundation of different information models, and the clarification of the models’ interrelationships. This is perceived as a contribution to a better understanding of the domains and how they relate to each other.Design for producibility (DFP) is the process in which a systematic method is used to reach the required functional properties of the product at the same time as good compliance with the manufacturing system is ensured. The DFP process usually needs to involve several persons simultaneously for the purpose of sharing information and knowledge. For many manufacturing companies, the collaboration between engineering design and production engineering is a critical issue and they have to improve their methods and tools for ensuring and enhancing producibility. This can be achieved by introducing computer-supported design for producibility. The present research is intended to contribute to the development and utilisation of different application systems that can be used as such computer support. The aim is to provide companies with support in application system development and to show how different application systems can be used in a systematic way as means to ensure and enhance producibility.

Many small and medium sized companies base their business strategy on their manufacturing processes. They are highly specialized in areas such as: die-casting, extrusion, machining, sintering, injection molding etc. The specialization is usually also focused on a limited number of material and alloys for the manufacturing process in question. These companies are commonly acting as subcontractors to other companies, original equipment manufacturers (OEMs). For the OEMs to be able to provide affordable products in a short time and to be at the competitive edge, every new design must be adapted to existing production facilities. In order to ensure this, collaboration between engineering design, at the OEM, and production engineering, at the subcontractors, has to be supported. With the dispersed organizations of today and the increasing amount of information that has to be shared and managed in the product realization process, this collaboration is a critical issue for many companies. A more intense collaboration is sought by many subcontractors as it will strengthen the business relation. To provide manufacturing knowledge and to be a partner in the product realization process is a means to outplay competitors.

The purpose of this work is to investigate, explore, and develop a computerized method, i.e. an application system, to support the process planning and cost estimation in the quotation process. The main objective is to reveal concepts and principles to support application system development and utilization. The results are based on the experiences from a case study at a subcontractor of turned components.

Design automation is an important means for efficient product configuration within an engineer-to-order business strategy. Commonly, the development of a design automation system is an iterative process alternating between top-down and bottom-up approaches. An overall strategy is a necessity for successful system development. However, to successfully structure the design process, retrace all the necessary knowledge and to close gaps in both the process and the knowledge definitions require a complete and detailed understanding of the design problem at hand. The objective with this work is to promote an iterative system development process characterized by the alternation between domain levels and to provide means for ensuring system completeness and functionality. The means introduced in this paper concern knowledge modelling and analysis in design automation systems. An information model, incorporating the concepts KnowledgeObject, Variable and KnowledgeObj_Parameter for knowledge modelling, and a database for the persistent data storage together with the principles of dependencies structure matrices (DSM), supports an iterative system development approach. Further, the quality of a design automation system, in terms of completeness and functionality, can be viewed and analysed continuously during system development, and system deficiencies can be traced by the use of different DSM views.

Initially, when implementing a design automation system the focus is on successfully developing a system that generates design variants based on different customer specifications, i.e. the execution of system embedded knowledge and system output. However, in the long run two important aspects are the modelling and management of the knowledge that govern the designs. The increasing emphasis to deploy a holistic view on the products properties and functions implies an increasing number of life-cycle requirements. These requirements should all be used to enhance the knowledge-base allowing for correct decisions to be made. In a system for automated variant design these life-cycle requirements have to be expressed as algorithms and/or computational statements to be intertwined with the design calculations. The number of requirements can be significantly large and they are scattered over different systems. The aim of the presented work is to provide an approach for modelling of manufacturing requirements, supporting both knowledge execution and information management, in systems for automated variant design.

A business strategy based on customized products with a high level of variety requires systems for efficient generation of product variants. An area identified in near collaboration with five industrial partners that has not been subject for extensive research is how to support management of different application domains, projects, task knowledge and design information together with the possibility to perform detailed analyses on the data generated by a design automation system implementation. Initially, a number of success criteria were identified and the functionality of a database was perceived as a promising approach. Explorative work was conducted for the purpose to reveal the conceptual model and the principles that a system would reside upon. The work has resulted in an approach, consisting of an information model and underlying principles, presented in this paper to be used when developing a design automation system for quotation preparation. The functionality and usefulness has been demonstrated and validated by a system implementation developed in collaboration with an industry partner. It can be concluded that a system founded on the presented approach supports management and analysis of quotations and product variants.

Many companies base their business strategy on customized products. To enable a high level of product adaptation in an engineer-to-order approach companies invest time and resources to develop design automation systems. Initially, when implementing a design automation system, the focus is on successfully developing a system that generates design variants based on different customer specifications (i.e. the execution of system embedded knowledge and system output). However, in the long run, two important aspects are the management and maintenance of the knowledge that governs the designs. Further, the increasing emphasis on deploying a holistic view of a product’s properties and functions implies an increasing number of life-cycle requirements. The knowledge to adapt the product to fulfil these requirements should also be used and consequently incorporated into the knowledge-base, allowing for correct decisions to be made. In a system for automated variant design, the implications on the product of these life-cycle requirements have to be expressed as algorithms, production rules and/or computational statements to be intertwined with the design calculations. The number of requirements can be significantly large, and the knowledge scattered over different application systems used for the realisation of the design automation system. This makes it difficult to manage and maintain the system as the product life-cycle environment changes and evolves. In this article, the focus is on the requirements related to manufacturing. For that, an approach for the modelling of manufacturing requirements, supporting both knowledge execution and information management, in systems for automated variant design is introduced. The approach has been applied and refined when developing a design automation system in cooperation with a company to demonstrate and verify the approach’s usability.

Subcontractors are frequently involved in quotation processes and the main objective of this work is to provide an integrated system foundation for quotation preparation that enables detailed analyses of product, process, and cost information. The technology, models and principles for successful system realization are described and a case example illustrating system functionality and utilization introduced. The system foundation enables flexible access to stored information supporting analyses across orders and product variants as well as on a more detailed level for individual product items.

The fact that application software are getting more and more adaptable extends the possibility of in-house developed design systems supporting design for cost. This calls for systematic methods for system development that ensure system functionality, quality and longevity.

In this work, a method supporting the development of automated systems for product design, process planning and cost estimation is introduced. The method has been the foundation on which an automated system for variant design has been developed. The system applicability as a means of gaining cost effective design is presented through studies of: multi-objective optimisation, what-if scenarios and sensitivity analyses. The work is completed by an evaluation of the three types of studies. This is followed by an evaluation of the variant design system and its underlying method (that supports in-house development of automated systems), with respect to a number of presented underlying general criteria supporting realisation of systems meeting companies’ needs.

The paper aims at presenting the thoughts behind concurrent cost estimation as a tool for engineering companies to obtain enhanced producibility for their products by the possibility of performing producibility studies. The two main parts of the paper are: the presentation of a method for system development, focusing on a number of general criteria of system development; and how such a system can act as a support in the product development process by providing the possibility of performing different types of producibility studies.

The demand on high levels of reliability and accuracy of cost estimation increases in a competitive environment and as the products are getting more optimised. When different courses of action are to be evaluated, changes in customer requirements, design features and parameters, and production properties have to be handled with caution. Even small changes can imply: low level of conformability with the production system, highly increased cost, and extended manufacturing lead-time. It is of paramount importance for the product success and the company’s profit that a system for automated producibility assessment is sensitive and can reflect these effects. Two central tasks in the development of such a system are the definition of a cost model and the modelling of producibility rules. Each organisation is very different and therefore has to define their individual cost model and set of producibility rules. This work presents an approach that provides a framework for the development of company specific automated producibility estimation systems. Further, the concepts of analysis driven and synthesis driven producibility estimations are described and some examples of their use are given.

A business strategy based on customized products with a high level of variety requires systems for efficient generation of product variants. The development of a system for automated variant design is a significant investment in time and money. To maintain the system’s usefulness over time, frequent updating of design rules and execution control will normally become a necessity. Significant efforts are required for maintenance and adapting an established system to changes in product technology, new product knowledge, production practices, new customers and so forth. Another important aspect that has been identified, is the reuse of the system encapsulated generic product family descriptions, for example design rules, when developing a new product family. In this paper a case study is presented with the objectives to provide an understanding and an insight into a real industrial case. A focus is put on the documentation and management of product related knowledge for the purpose of revealing problems related to the current state of practice at the company to identify areas for improvements. The results are based on the experiences from a case study at a company with long experience of systems for automated variant design.

The demand on the level of reliability and accuracy of cost estimation increases in a competitive environment and as the products are getting more and more optimised. When different courses of action are to be evaluated small changes in customer requirements, design features and parameters, and production properties has to be handled with caution. Small changes can imply: low level of conformability with the production system, highly increased cost, and extended manufacturing lead-time. It is of paramount importance for the product success and the company’s profit that a system for automated cost estimation is sensitive and can reflect these effects. Design automation system incorporating producibility and cost estimations support either analysis driven or synthesis driven producibility estimation, or both. The later is an approach that allows for decreased recourse and time demand as the system only generates design proposals which the company can produce with its manufacturing resources. This work presents some of the views on which a design automation incorporating producibility and cost estimations should by developed. It also presents the concepts of analysis driven and synthesis driven producibility estimation and gives some examples of there use.

For many products, the adaption to customer specifications is essential and requires flexible product design and manufacture while maintaining competitive pricing. A large category of design work in industry has the character of the redesigning of an existing product concept in terms of dimensional changes, topology variations and the configuration of components. In order to evaluate design proposals, costs, controlled by the product design, selected materials and manufacturing processes, need to be estimated. Cost estimates are normally based on the manufacturing process plans. They, in turn, can only be formed when production preparation is finalised. The widespread industrial use of solid modelling opens up new possibilities for automating this process. The purpose of this work is to demonstrate and test a method of extracting product information from a CAD model in order to allow process planning and cost calculation to be carried out automatically for a given class of products. With such a system, cost estimates can be made available to the designer the instant a design proposal has been presented. This allows design iterations to be carried out, in order to govern the design work towards solutions with an optimal balance between product and production properties.

With today’s high product variety and shorter life cycles in automobile manufacturing, every new car design must be adapted to existing production facilities so that these facilities can be used for the manufacturing of several car models. In order to ensure this, collaboration between engineering design and production engineering has to be supported. Sharing information is at the core of collaborative engineering. By implementing an ontology approach, work within domains requirement management, engineering design and production engineering can be integrated. An ontology approach, based on an information model implemented in a computer tool, supports work in the different domains and their collaboration. The main objectives of the proposed approach are: supporting the formation of requirement specifications for products and processes, improved and simplified information retrieval for designers and process planners, forward traceability from changes in product systems to manufacturing systems, backward traceability from changes in manufacturing system to product systems, and the elimination of redundant or multiple versions of requirement specifications by simplifying the updating and maintenance of the information.

Many companies base their business strategy on customized products with a high level of variety and continuous functional improvements. For companies to be able to provide affordable products in a short time and be at the competitive edge, every new design must be adapted to existing production facilities. In order to ensure this, collaboration between engineering design and production engineering has to be supported. With the dispersed organisations of today combined with the increasing amount of information that has to be shared and managed, this collaboration is a critical issue for many companies.

In this article, an approach for sharing and managing product and production information is introduced. The results are based on the experiences from a case study at a car manufacturer. By ontology-based integration, work within domains engineering design, production engineering and requirement management at the company was integrated. The main objectives with the integration were: support the formation of requirement specifications for products and processes, improve and simplify the information retrieval for designers and process planners, ensure traceability from changes in product systems to manufacturing systems and vice versa, and finally, eliminate redundant or multiple versions of requirement specifications.

With today’s high product variety and shorter life cycles in motor car manufacture, every new car design must be adapted to existing production facilities so that these can be used for several car models. Sharing information is at the core of collaborative engineering. With an ontology approach, the work within the domains requirement management, engineering design and production engineering can be integrated. An ontology approach based on an information model implemented in a computer tool supports the work in the different domains and their collaboration. In our work we make use of the existing structures and link those using appropriately named links. We also propose the introduction of a new structure describing the generic functions of the manufacturing system, MSF. This tree structure is a suitable tool to link product related objects to their associated production equipment at varying levels of detail. The manufacturing requirements are modelled using a concept for the definition of the requirement content, called Manufacturing Requirement (MR). To enable the MR to cover different ranges and levels, and enhance the maintenance of the system integrity, the concept of Requirement Object is introduced. The RO is used to collect the instances for which a specific MR is valid. We also use the rule inference facility to reduce the number of explicitly defined relations.

To stay competitive, PM manufacturers have to be able to accept a wide range of components with different features and properties. Thus, it is of utmost importance for manufacturers to adapt their common process routes to new requirements as rapidly and economical as possible. The procedure of identifying the right route among all the alternatives requires abundance of experience and knowledge and is a crucial and time-consuming decision; usually made by a team of engineers. In this study, by considering the mechanical properties and design specifications of the final component, a simple methodology is developed to aid the engineer(s) in selection of the optimum PM process route. In order to sort the possible routes according to cost, a cost estimating module has been devised. The total concept is applied to a case studyies and its accuracy has been evaluated.

For parts suppliers in the manufacturing industry, the process of preliminary production preparation and the subsequent calculation of offers are critical business activities. A vital part of production preparation is the design of fixtures and tooling necessary for many processes of metal forming. In order for a company to give quick responses to customer enquiries or changes in prior specifications, it would be highly beneficial with a degree of automation in this design process. This implies the development of a computer based system able to capture existing design procedures and associated knowledge for the classes of tooling required for the forming process.

In this work, an implementation for the rotary draw bending of aluminum tubing has been done to exemplify how to develop an automated design system. The system is based on heuristic knowledge developed over many years of practical experience, knowledge analytically derived from fundamental theory found in scientific literature, and rules based on empirical data from trial manufacturing. The system applies knowledge to a given specification that a skilled engineer otherwise would do manually. The system output can be used to evaluate whether a tube is producible.

The main idea behind the system is to use knowledge objects containing information on inputs, outputs, constraints and what software are used to implement the knowledge pieces. This approach makes the system highly flexible and allows for multiple types of knowledge that might overlap. When an offering calculation is wanted, the system is set to run applicable knowledge objects for presented input data. Other objects are run when an accurate calculation for detailing is wanted for a more detailed set of input data. The system is built on readily available commercial software packages connected with a simple Visual Basic .Net program.

When building a system of this kind, it is essential that the knowledge documentation and structure be such that the functions of the system can be easily understood by the users of the system and by future developers. Aspects of user friendliness, transparency and scalability are addressed in the summary of this paper.

Manufacturing companies are required to develop and produce products that meet increased requirements from customers and investors on shortened time spans. One key factor in meeting these requirements is the efficiency of the product development and the production preparation process. Design automation is a powerful tool to increase efficiency in these two processes. The benefits of automating the production preparation process are shortened lead-time, improved product performance, and ultimately decreased cost. Further, automation is beneficial as it increases the ability to adapt products to new product specifications with production preparations done in few or in a single step. During the automation process, knowledge about the production preparation process is collected and stored in the corporation systems, thus allowing full control over the design of production equipments.

The contribution of this work is a method for connecting knowledge pieces implemented in auxiliary software applications using an inference engine. The knowledge pieces can control CAD-models and automatically generate, execute, and interpret finite element analyses. The presented method allows the automation of corporation know-how developed by skilled engineers over time. Further, it is possible for the resulting systems to meet criteria for good design automation systems such as low effort of developing, low level of investment, user readable and understandable knowledge, scalability, and flexibility.

The method is exemplified by an implementation for analyzing manufacturability of the rotary draw bending of extruded sections of aluminum where the sections are complex. The output from the example system is based on established design practice and heuristic knowledge developed over many years of practical experience, rules analytically derived from fundamental physical laws, and finite element calculations. The system applies knowledge to a given specification that a skilled engineer otherwise would do manually. The method is described along with the example system in this paper.

Increased pressure on manufacturing companies to develop and produce products that meet tightened requirements from customers and investors on shortened time spans require increased efficiency of the product development and the production preparation. Design automation is a powerful tool to increase the efficiency in these two processes.

The benefits of automating the production preparation process are shortened led-time, improved product performance, and ultimately decreased cost. Further, automation is beneficial as it increases the ability to adapt products to new product specifications with production preparations done in few or in a single step. During the automation process, knowledge about the production preparation process is collected and stored in company systems, thus allowing full control over the design of production equipments.

Finite element analyses (FEA) are often used to test product properties virtually. The process of setting up FEA is many times manual and not strictly formalized; the assumptions made in those calculations highly depend on the analysts’ former experiences and gut feeling. Sometimes there exist parametric FEA-models, but they are hard to interpret for others than the developers. It is beneficial to formalize and automate the process of developing such calculations in order to automate the production preparation of mature and variant-rich products where estimations and validations using FEA are demanded in the whole or parts of the design space. Automating the FEA-process for selected production methods makes the dedicated FEA-models more flexible and more transparent. It also makes them live longer and be more available for engineers that are not FEA-specialists. The FEA-specialists will have more time to solve general problems rather than focusing on instances of the product.

This work deal with the automation of FEA-based producibility analysis of aluminium tubes with several bends, as is a part of the production preparation of many products. The method proposed includes the usage of a KBE-system that handles knowledge objects that connect to auxiliary software applications. This is done in order to generate a design synthesis based on product specifications, to develop a geometrical model of the synthesis in a CAD-system, to generate mesh parts in a CAD-system, to set up and run a FEM-calculation based on the generated mesh, and finally to extract required results from the calculation result files. The complete process of bending the tubes several times is automatically synthesised and analysed.

Intensive competition on the global market puts great pressure on manufacturing companies to develop and produce products that meet requirements from customers and investors. One key factor in meeting these requirements is the efficiency of the product development and the production preparation process. Design automation is a powerful tool to increase efficiency in these two processes.

The benefits of automating the production preparation process are shortened led-time, improved product performance, and ultimately decreased cost. Further, automation is beneficial as it increases the ability to adapt products to new product specifications with production preparations done in few or in a single step. During the automation process, knowledge about the production preparation process is collected and stored in central systems, thus allowing full control over the design of production equipments.

Three main topics are addressed in this thesis: the flexibility of design automation systems, knowledge bases containing conflicting rules, and the automation of the finite element analysis process. These three topics are discussed in connection with the production preparation process of rotary draw bending.

One conclusion drawn from the research is that it is possible to apply the concept of design automation to the production preparation process at different levels of automation depending on characteristics of the implemented knowledge. In order to make design automation systems as flexible as possible, the concept of object orientation should be adapted when building the knowledge base and when building the products geometrical representations. It is possible to automate the process of setting up, running, and interpreting finite element analyses to a great extent and making the automated finite element analysis process a part of the global design automation system.

For parts suppliers in the manufacturing industry the process of preliminary production preparation and subsequent calculation of offers are critical business activities. A vital part of production preparation is the design of fixtures and tooling necessary for many processes of metal forming. For a company to give quick responses to customer enquiries, or changes in prior specifications, it would be highly beneficial with a degree of automation in this design process. This implies the development of a computer based system able to capture existing design procedures and associated knowledge for the classes of tooling required for the forming process.

In this work we exemplify an automated design system for tooling by an implementation for rotary draw bending of aluminium tubing. The system is based on established design practice and heuristic knowledge developed over many years of practical experience. The system will evaluate whether a given specification is producible with existing materials and equipment, select suitable machine, determine process parameters and determine type and dimensions of components of form die, clamp die, follower or pressure die, wiper and mandrel. The system is built on readily available commercial software packages. When building a system of this kind it is essential that the knowledge documentation and structure is such that the functions of the system can be easily understood by the users of the system and by future developers. Aspects of user friendliness, transparency and scalability are addressed in the summary of this paper.

It has become more and more common for companies to move part of their production to low cost countries and/or closer to important markets. However, quite often the product development is not moved. The result is an increased distance between product development and production. The interface between the two departments is important to lead time, cost and quality and therefore the cooperation must work smoothly. To achieve this, most literature recommends early and tight cooperation. However this can be complicated by expensive and time consuming travels and/or usage of less rich communication such as emails and phone calls.

It is difficult to make the transition in general from product development to production and the possible problems increase with the distance. The PD-P interface consists of several components and how a problem in one component is affected by problems in other components is not explicitly discussed in literature. The purpose in this paper is to explore if there are such connections i.e. connections between an observable problem and other components in the PD-P interface in a geographically dispersed setting. The paper does so by merging the distributed work literature and the PD-P interface literature.

The analysis is based on four PD-P interface components; technological, organizational, scope and task. The analysis indicates that observable problems as e.g. low frequency of communication can be the symptom of one or a combination of problems. Connections between the components in the PD-P interface are exemplified in a geographically dispersed setting. Furthermore the underlying causes to the problems connected to the geographically dispersed setting in the PD-P interface are elucidated. In the case of low frequency of communication, it could be the technical system hindering communication and the different time zones disrupt it even more. Hence one symptom could be caused by different underlying problems. Each problem needs to be broken down to find the cause and the solution could be found in any of the four interface components.

The results indicate that the actual distance is not the biggest problem but uncertainties (e.g. new collaborations) and differences (culture and work methods) which increase lead time. We have also seen that single underling problems can cause problem in several of the PD-P interface components. This indicates that if these underlying problems can be solved the project results can be vastly improved. For example, trust issues occur in the scope component (affects the willingness to share information) and in the organizational interface component (both competence trust and goodwill trust affects involvement and commitment to the project). Consequently, if problems like this can be solved many other problems will become minor problems and project objectives will be more likely to be obtained. However trust is difficult to achieve with a geographical distance between product development and production. The analysis also indicates that due to the distance more attention is paid to the PD-P interface, e.g. more experienced team members are appointed. This can be contributing to a smoother PD-P interface than expected.

The cooperation between firms and academia is often seen as an effective way to provide disciplinary skills and knowledge of system building for inexperienced students. In theory, cooperation has many advantages: The students get first-hand knowledge of the industrial environment and experiences of working with professional designers. In this way they get an opportunity to feel the pace of realistic projects as well as an opportunity to show their skills for future employment. Not only the students benefit from this cooperation; the firms gain new innovative ideas and knowledge of the latest development techniques. They also get good leverage on the resources invested since the amount of hours spent by the student teams could be tenfold the contribution of the firms.

In real life, the cooperation between firms and academia can be both time-consuming as well as troublesome. One reason for this is that their objectives are different: The teachers want the students to learn and the companies want to make money. To overcome unnecessary barriers in cooperative design projects, a set of guidelines have been created at the School of Engineering at Jönköping University in Sweden. The guidelines have been developed from the experiences of collaborating with more than 30 different companies between the years 2000 and 2006. One finding is the importance of aligning the expected project outcome between students, teachers and companies. Another important aspect is to ensure that the standard of the work is high enough in order to satisfy the firms. This is achieved by a careful selection of projects and by comprehensive coaching of the students using a proven framework of learning design.

Set-Based Concurrent Engineering is sometimes seen as a means to dramatic improvements in product design processes. In spite of its popularity in literature, the number of reported applications has so far been limited. This paper adds new information by describing implementations of Set-Based Concurrent Engineering in four product developing companies. The research took a case study approach, with the objective to investigate if the principles of Set-Based Concurrent Engineering can improve the efficiency and the effectiveness of the development process. The study shows that set-based projects can be driven within an existing organization, if given proper support. The participants claim that a set-based approach has a positive effects on development performance, especially on the level of innovation, product cost and performance. The improvements were achieved at the expense of slightly higher development costs and longer lead time. However, the positive effects are dominating and the companies involved intend to use Set-Based Concurrent Engineering in future projects when appropriate.

Decision-making and selection of different design alternatives is a central activity in product development. This paper compares the decision process of Set-Based Concurrent Engineering to Pugh’s method of controlled convergence in an industrial case study. The purpose is to investigate if the set-based decision process renders different results compared to the traditional Pugh matrix selection. In the case study, Pugh’s matrix promoted the development of new concepts. The set-based process offered the opposite approach, aiming at improving the currently used technologies.

For the last seven years a successful cooperation between courses in product design and industrial design has been running at the School of Engineering at Jönköping University (JTH), Sweden. The concept of fusing separate courses with different domains of knowledge into one project is of course well known by most teachers, but this course takes this form of education one step further. This paper will describe the experience of coaching over 90 design-build-test projects going through the steps design, build, test but also the steps of fail and learn.

This paper describes experiences from implementation of Set-Based Concurrent Engineering in four different product developing companies. The objective was to investigate if the principles of Set-Based Concurrent Engineering can improve the efficiency and the effectiveness of the development process in industrial cases, but also to identify barriers for its implementation. The study shows that set-based projects can be driven within an existing organization, given the proper support. The participants claim that a set-based approach gives positive effects on development performance, especially on the level of innovation, product cost and performance. The improvements were achieved at the expense of slightly higher development costs and longer lead time. However, the positive effects are dominating and the companies involved intend to use Set-Based Concurrent Engineering in future projects when appropriate.

The work described in this paper seeks to minimize the time spent on manually reducing thin-walled CAD-geometry into surface idealizations. The purpose of the geometrical idealizations is the creation of shell element meshes for FE-calculations. This is motivated by time and thereby cost savings and also to make the results of the calculations available earlier in the product development process allowing the results to guide the designs to a larger extent.

Systems for automated geometry idealization and creation of FE-models already exist, but this paper describes a novel approach with the working principle of analyzing how the CAD-specific features of the CAD-file history tree are constituted. This information is used to automatically create the best practice geometrical idealization in the same CAD-model.

Evaluation of the performance of the system in an industrial example is also presented.

This report presents a method for constructing the mid-surface of CAD models of parts requiring tooling for their manufacture. The mid-surface is constructed by sectioning the CAD-model in a sufficient number of places along the draft direction. In each section the mid-segments of the sectioned material is constructed. The complete mid-surface is obtained by connecting the individual mid-segments with the closest located mid-segment in the adjacent sections. The intended use of the method is computer implementation to automatically derive the mid-surface from CAD-models to be used as target geometry for FEA shell element meshing. The feasibility of the method is demonstrated by applying it to a CAD-model. In this example a target surface is constructed using both the conventional and the sectioning method. The target surfaces are used to create shell element FEA models.When solved, the natural frequencies of the two models are almost the same. This shows that the sectioning method is an alternative way of creating the target geometry. The intention is to use the method to create an automatic tool for mid-surface extraction with better performance than today's commercially available tools.

The aim of the present paper is to dissolve the bottleneck for PM market expansion caused by lack of knowledge among designers about PM-specific design principles by proposing an automated PM-part advisory system. The system, called PM-Wizard, checks that a PM-part design suggestion represented as any 3D solid CAD-model complies with the geometrical design rules and recommendations for PM-parts. The system consists of a rule-base hosted by a modern commercial CAD/CAE-system and a programmed algorithmic procedure that converts the design suggestion into a specially developed format. The format enables the automated evaluation of the PM-part in the receiving CAD/CAE-system informing the designer on how the geometry should be revised to facilitate the pressing. The conversion algorithm has been tested on a large number of PM-parts, and the result is that all the tested parts can be converted into the proposed format and successfully evaluated.

Product development has both innovative and analytic sides. Starting from the requirements, a design suggestion is generated. In order to assess how well the envisioned design fulfils the requirements, it is sometimes necessary to build a computer model of it for the analysis. The overall motivation of the work presented is to reduce the time spent on creating the model by reusing knowledge gained from developing similar products by suggesting, building and evaluating IT-systems. To verify the systems real design examples, obtained from companies that have participated in the research projects have been used.

The work is based on two major application examples. The first, involving the automated geometrical idealisation of die-cast parts (Paper I-III), and the second involving manufacturability of powder metallurgy pressed and sintered parts (Paper IV-VI). The work starts from the point in the product development process where it exists a design suggestion represented as an arbitrary format CAD-model. In the powder metallurgy case the object is to secure that the geometry is suitable for the production process. In the die-casting case the object is to automatically create an idealised version of the model for shell elements meshing. These two tasks have previously been treated as two separate cases, addressed by completely different software. This thesis suggests a common method for addressing the two cases. The method is based on converting the CAD-models, using the geometrical restrictions of the production processes, into a format with a specialised feature structure, parameterisation and construction history using a feature recognition approach. The features are then automatically reconstructed in a target CAD-system. The resulting, specialised CAD-model can be used for automated design and design evaluation purposes, demonstrated in the thesis. The models are therefore called DAR (Design Automation Ready)-models. The DAR-models are useful in that they separate the conversion from the subsequent treatment of the models providing modularisation, flexibility and user insight in the model structure. In that a construction history and parameterisation have be constructed in the target CAD-system, the advanced geometry manipulation and means for knowledge management often provided in modern CAD-systems can be accessed in a transparent and user manageable way. This extends the usefulness of the CAD-systems from involving only interactive work to managing all components sharing the same production process.

CAD-models of parts produced by injection moulding or die-casting are often complex making the task of automated geometrical idealisation for finite element analysis difficult. Conventional tools for geometric idealisation are not ideal for the task, as will be shown in the thesis. To address the idealisation problem, this thesis proposes a novel method of creating geometric idealisations of CAD-models for finite element analysis. Knowledge about the production and design processes is used to support the idealisations. The key idea is to simplify the idealisation problem by using the fact that die-cast and injection-moulded parts have a clearly defined tooling draft direction. It is primarily the mid-surfaces of the thin-walled geometry that are extracted for shell element meshing. The ideas have been tested by the creation of a CAD-integrated system that reads the construction history tree of the CAD-model and creates an idealised geometry in the same CAD-model automatically. It is also shown how the system can be used for idealising neutral format files by creating a virtual construction history tree in interaction with the user. The system is named CASTING (CAd Supported Tool for Idealisation of Geometry). The overall objective is to save time in the idealisation step, thereby freeing time for more creative work in the design process.

This paper presents a newly developed CAD-integrated system for the manufacturability evaluation of designs of powder metallurgy (PM) pressed and sintered parts. The contribution of the paper is the automated reconstruction of a specialized construction history tree from any CAD-model directly in the receiving CAD-system. The reconstruction is based on the geometrical restrictions of the shapes that can be manufactured by the PM process. This facilitates the creation of a transparent and user-revisable rule-base to evaluate the parts manufacturability, which is shown. It will enable designers to get feedback on their designs, reducing the number of design loops with the PM-parts supplier needed before the parts geometry can be established.

In order to codify, manage, and reuse the knowledge gained from pursing product development projects, CAD-programs have started to provide functionality for supporting this activity. Since the primary purpose of the CAD program is to interactively define geometry, the functionality has been integrated primarily to be used on the parameters of the CAD-model of the design instance. This paper explores how the functionality can be used in a broader scope, managing and automatically reusing knowledge for all designs intended for a certain production process. This is facilitated by automatically converting an arbitrary CAD-model of a design to a format that is accessible for knowledge handling and reuse functionality in the CAD-system. A conversion algorithm for the processes die-casting and powder metallurgy pressing sintering is presented, as well as showing how the knowledge can be represented in the CAD-system. This will allow engineers to actively participate in the knowledge build-up and insure that the general knowledge can be handled in the companies’ IT-infrastructure.

Parts for trimmers, lawnmowers and chainsaws are often manufactured by die-casting in light alloys. These parts often have a complex geometry with thin-walled regions mixed with regions of non thin-walled geometry. This paper discusses the process of creating FEA-models from CAD-models of such parts. The objective of the FEA, in the particular case described in this paper, is to predict the performance of the complete products. Since a FEA-model of the complete product require extensive computational power to solve, it is necessary to keep the computational cost down by f. ex using shell-elements instead of solid-elements where applicable.

The creation of the shell-element mesh based on the solid CAD-model can be time consuming, especially if the CAD-model is complicated as often the case in real products. To aid in the creation of the shell-element mesh there is commercial software available for the extraction of the mid-surfaces in the CAD-model. In this paper two different software for mid-surface extraction are tested, both included in pre-processors for high-end FEA solvers. The software was tested on six different die-cast or injection moulded parts, all components in consumer products available on the market.

The result is that the software can extract the individual mid-surfaces well but the connections between them are often not created properly.

Furthermore the software cannot, as expected, deal with the regions that divert too much from being thin-walled. This paper present an idea on how treat these regions by retrieving suitable representations from a depository of representations known from experience to represent the geometry well and insert them in the appropriate position in the FEA-model automatically.

To show the feasibility of the idea a demonstrator program created in CATIA V5 using VBA is also presented in this paper.