Over 70% of final product costs are determined by initial product design. Hence, to depict a capable and reliable part design is important during the part conceptual design phase. Case-Based Reasoning (CBR), based on analogical reasoning, is a problem solving methodology. This paper proposes the CBR architecture applied to assembly part design for effectively managing previous design experience and evaluating assemblability and manufacturability of assembly part design. The results can provide a useful reference for novices to reuse and revise previous experience and experienced designers to impart their expertise through CBR methodology.

Sammanfattning Det är allmänt känt att global uppvärmning är ett problem som grundar sig i att för mycket växthusgaser släpps ut. Detta måste förändras för att effekterna av global uppvärmning inte ska förstöra viktiga ekosystem. Av Sveriges industrier orsakar stålindustrin den största negativa miljöpåverkan, stålindustrin är därför ett av de främsta områdena att minska miljöpåverkan inom. För att minska miljöpåverkan krävs en metodik, som även sänker kostnaden på produkten.  Studien resulterade i en arbetsmetodik genom att använda beprövade metoder och jämföra mot en referenskonstruktion. Beprövade metoder som tillämpades för att minska miljöpåverkan, kostnaden samt uppnå kundkraven var: Topologioptimering, modulär konstruktion, Design for Manufacture and Assembly, och Lean Construction. Design for Environment diskuterades även.  Nulägesanalys utfördes för att skapa underlag till genomförandet av metoderna.  Metoderna tillämpades genom koncept som kartlades i ett miljö- och kostnadsdiagram tillsammans med referenskonstruktionen. Metoderna utvärderades genom tolkning av diagrammet och kundkravsmatris. Utvärderingen resulterade i en slutgiltig metodik som beprövades genom ett slutgiltigt koncept. Den slutgiltiga metodiken validerades med det slutgiltiga konceptet. Arbetet resulterade i en arbetsmetodik, följande arbetsmetodik är en förkortad verision: (1) Entydiga kundkrav; (2) flera koncept med målet att minska variationen och förenkla; (3) utvärdera konceptens möjligheter till modularisering; (4) det bästa konceptet väljs; (5) spänningsanalysera konceptet för att kunna justera överdimensionerade delar; (6) applicera DfMA råd, minska antalet delar som kräver lyftanordning vid montering. Arbetsmetodiken validerades genom att skapa ett slutgiltigt koncept. Konceptet uppfyller samma krav som referenskonstruktionen. Tidigare koncept har genomförts på en avgränsning av referenskonstruktionen, vilket medförde att delar av koncepten beaktades i den slutgiltiga arbetsmetodiken. Det kan ha medfört en viss felmarginal i valideringen. Om fler referenskonstruktioner var tillgängliga kunde valideringen gjorts annorlunda. / Summary Global warming is a commonly known problem based on the amount of greenhouse gas emissions; a change is therefore necessary for important ecosystems not to be disrupted. The steel industry sector accounts for the largest environmental impact of Swedish industry, which makes it one of the most important areas for improvements to be made [1]. To reduce the environmental impact, a method is required which also lowers the cost of the product. This study resulted in a methodology by using proven methods and comparing against a reference construction. The following methods that were used to satisfy the customer requirements and striving towards environmental and economic sustainability were: Topology optimization, modular construction, Design for Manufacture and Assembly, Lean Construction, Design for Environment was discussed. A situation analysis was preformed to create a basis for the implementation of the methods. Application of the methods was carried out by mapping the concepts in an environment-cost-diagram with the reference. The methods were evaluated by interpreting the diagram and Pughs matrix, the evaluation resulted in a methodology that was applied through a final concept. The work resulted in a methodology, which is presented in a shortend verision: (1) Clear customer requirements; (2) several concepts with the goal of reducing variation and simplifying; (3) evaluating the concept's possibilities for modularization; (4) over all best concepts is selected; (5) Stress Analysis on the selected concept to make adjustment on oversized parts; (6) apply DfMA advise, reduce the number of parts that require lifting equipment during assembly. The method was validated by creating a concept with the final methodology. The concept met the same requirements as the reference construction. Part of the reference construction has eariler been made concepts of, which led to ideas of the earlier made concepts were taken on to the final concept. This led to certain margin of error in the validation. If other reference constructions were available, validation could’ve be done differently.

Substantial benefits can be achieved through the adoption of lean type thinking earlier at the design stage to create more viable products. A complex design cannot be easily leaned out in production; therefore, the production of affordable and sustainable products requires effective lean design considerations at the conceptual level. The research presented in this thesis investigates and demonstrates the application of lean design for product enhancement. The aim of the research was to develop a novel lean design framework that would support the generation of product design with attributes such as maximise value, manufacturable, and operable with minimum waste and resources ensuring avoidable harm is eliminated. The framework consists of a systemised process which is organised in to phases and activities that provides a unique practical manner to lean out a design. The construction of the framework initiated with an extensive literature review and proceeded with an industrial field study which consisted of 34 interviews with 11 manufacturing companies in Europe. The findings were amalgamated to generate a lean design definition and principles which would form the foundations of the framework. A real-life industrial case study of an offshore oil/water separator was used to validate the framework. In conclusion, the lean design framework provides the necessary means by which a lean design can be achieved. As a result a functionally viable and enhanced design that is cheaper to manufacture through controlling waste and eliminating avoidable harm occurrence can be realised with minimal effort. The research makes the following contributions: (1) identification of essential elements in lean design, (2) generation of a lean design definition and principles, (3) Lean Design Framework development and (4) illustrative guidelines based on the framework to be used by designers in realising a lean product design.

由於大環境的改變，公司間的競爭越來越激烈；顧客對新產品的需求也因為新技術的出現日益增加。為了因應全球化競爭及產品生命週期縮短的大環境，迅速及優異的新產品發展成為公司重要的競爭優勢。為了強化公司的競爭優勢，新產品發展已成為一重要議題。本論文著重於研究改善新產品發展的過程，探討影響新產品發展的關鍵因素，尤其是生產與研發間的關係。 本論文分為五個部分，第一章探討新產品發展的概念及基礎理論，說明新產品發展從單一功能政策進化為今日的跨功能性政策的一環。第二章對影響新產品發展的關鍵因素做詳盡介紹，說明跨功能性的整合將會是新產品發展成功的關鍵方法。第三章仔細討論研發與製造間的關係，並將兩者的角色由傳統的分別為單一部門功能的觀點打破，且將產品的設計與製程均視為新產品發展的重要功能，試圖詮釋將單一個人╱部門的知識與成功的新產品發展連結的可能性。第四章將探討知識傳遞的限制、知識管理及組織學習的基本理論。第五章將介紹重要的管理上、組織上及技術上的支援工具，並希望藉由這樣的分析能夠瞭解新產品開發過程中各關鍵因素間的關係。第六章將介紹實務上所使用的新產品開發觀念，這部分的資料是由個案訪問而來，選了三家不同產業具國際營運的公司為例，對實務做驗證。最後，提出一新產品開發的「最佳實務」，包括了重新定義新產品開發過程中的功能，並提出一良好管理新產品開發的建議。 / Nowadays the competitions among companies become more and more fierce due to the dramatic change of competitive environment. The demands of new products are accelerated by the emerging new technologies. The rapid and excellent new product development (NPD) has become a great strategic advantage to be accommodated to the global competition with shorter product life cycle. In order to enhance the competitive advantage, improving NPD has become a vital issue for companies. This thesis focuses on improving the NPD process. Factors influencing the NPD process are discussed in detail, especially the interface between R&D and production. The thesis is divided into five parts, starting with a general view on NPD in the first chapter. There it will be shown, how NPD has changed over the last decades from a traditional approach of functional-development to a cross-functional process today. Factors influencing this effective collaboration are presented in chapter two. In chapter three, the interface between R&D and production is directly scanned. It will be distinguished between the individual knowledge bases of the different departments. Process and product knowledge can be identified as the parts to be matched and will be illustrated. Consequently, the possibilities of linking those knowledge bases during NPD are shown. Chapter four will focus on the limitations of knowledge transfer and the fundamentals of knowledge management and organizational learning will be presented. In chapter five, supportive organizational, managerial and technological tools will be analyzed. The multiple views on NPD assure that all factors influencing the process are analyzed and proven according to their leverage on the process. In chapter six, currently used NPD concepts are outlined. The information presented was gathered through interviews carried out at globally operating companies who have technological centers and production sites in Sweden. To avoid focusing on NPD practices in an industry, the companies were chosen according to their product lines and customer segments. The final part will present best practices in NPD. This includes reconsidering all the discussed aspects and presenting a recommendation about how to organize NPD superiorly.

In product manufacture and assembly it is important to lower materials usage and assembly timewhile retaining a safety margin against structural failure. In this project the ceiling attachment of theAVPOS offloading arm is redesigned based on objectives identified by Löfs Specialmaskiner. Theoriginal ceiling attachment is analysed using finite element analysis to identify any structuralweaknesses to be addressed during redesign. Based on information gained during the FEA threeconcepts are generated and rated based on their estimated assembly times, material usage, partscount and the cutting length for machining.One concept is selected for further topology optimisation and iterative FEA, where material isremoved from the selected concept design while maintaining safety objectives. The optimised designdeveloped during this project is shown to have a lower number of parts, lower usage of material andassembly time while retaining an overall FOS value of 4.In addition to redesigning the ceiling attachment, alternative bearings are also investigated whichchanges the existing ball bearings to a self-aligning sliding bearing with self-lubricating properties,lowering the machining tolerances as well as lowering the needs for service.This project contributes to lowering material usage and ease of assembly in the product AVPOS thatis manufactured by Löfs Specialmaskiner. The redesigned ceiling attachment along with thesuggested bearings will likely simplify future manufacturing as well as lower any concerns for damageto people and property as a result of structural failure.