Fredrik Elgh

Cost Engineering for manufacturing: Current and future research

The article aims to identify the scientific challenges and point out future research directions on Cost Engineering. The research areas covered in this article include Design Cost; Manufacturing Cost; Operating Cost; Life Cycle Cost; Risk and Uncertainty management and Affordability Engineering. Collected information at the Academic Forum on Cost Engineering held at Cranfield University in 2008 and further literature review findings are presented. The forum set the scope of the Cost Engineering research, a brainstorming was held on the forum and literatures were further reviewed to understand the current and future practices in cost engineering. The main benefits of the article include coverage of the current research on cost engineering from different perspectives and the future research areas on Cost Engineering.

Supporting management and maintenance of manufacturing knowledge in design automation systems

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 products 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 approachs usability.

Automated engineer-to-order systems – a task-oriented approach to enable traceability of design rationale

Mass customization is a rapidly growing business model that enables companies to deliver products with increased customer value. The ability to design and manufacture highly customer adapted produc ...

Documentation and Management of Product Knowledge in a System for Automated Variant Design: A Case Study

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.

Decision support in the quotation process of engineered-to-order products

Sub-suppliers acting in the supply chain of the car industry have to adopt a strategy of products customization to be at the competitive edge. This is caused by the diversity of clients requirements that entails customer engineered products with a high level of variety. A business strategy based on engineered-to-order products requires systems for efficient generation of product variants. This also includes a need of decision support in the order preparation process as well as in the quotation preparation process. Decision support that gives access to detailed and accurate information in the quotation preparation enables a high level of product adaptation while ensuring company efficiency. By the introduction of a design automation system, this can be achieved. However, means to manage different application domains, projects, task knowledge and design information are required together with a possibility to perform detailed analyses on the system generated information. The objective of this work is to contribute in that area. Initially, a number of success criteria were identified and explorative work was conducted for the purpose to develop a conceptual model and principles that an application system would reside upon. The result is a framework consisting of an information model and underlying principles to be used when developing a design automation system for quotation preparation. A system founded on the framework supports management and analysis of quotations and product variants. The functionality and usefulness has been demonstrated and validated by a system implementation developed in collaboration with an industry partner.

Cost-based producibility assessment: analysis and synthesis approaches through design automation

Abstract The demand on high levels of reliability and accuracy of cost estimation increases in a competitive environment and as the products are getting more optimized. 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 companys 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 organization 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.

Modelling and Management of Manufacturing Requirements in 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 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 Generic Framework for Automated Cost Evaluation of Product Variants and Fabrication Plants

Cost is one of the most important criteria for 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 with an optimal balance between product and production properties. The starting point of the proposed procedure is the cost structure of a manufactured product: identification of information needed for 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.

An Ontology Approach to Collaborative Engineering for Producibility

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 systems to product systems, and the elimination of redundant or multiple versions of requirement specifications by simplifying the updating and maintenance of the information.

Enhancing the Efficiency and Accuracy in the Quotation Process of Turned Components

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, inje ...