The ability to innovate and launch customized products that are well matched to customer demands is a competitive factor for many manufacturing companies. Development of highly customized products requires following an engineer-to-order business process to allow the products to be modified or adapted to new customers’ specifications, which brings more value to the customer and profit to the company. Design of a new product variant involves a large amount of repetitive and time consuming tasks but also information handling activities that are sometimes beyond human capabilities. Such work that does not rely so much on creativity can be carried out more efficiently by applying design automation systems. Design automation stands out as an effective means of cutting costs and lead time for a range of well-defined design activities and is mainly considered as a computer-based tool that processes and manipulates the design information. Adaptation and variant design usually concern generating a new variant of a basic design, which has been developed and proved previously, according to new customer’s demands. In order to efficiently generate a new variant, a deep understanding of the previous design is essential. Such understanding can be achieved by access to the design rationale explaining the reasons and justifications behind the design. Maintenance of design automation systems is essential to retain their usefulness over time and adapt them to new circumstances. New circumstances are, for example, introduction of new variants of existing products, changes in design rules in order to meet new standards or legislations, or changes in technology. To maintain a design automation system, updating the design knowledge (e.g. design rules) is required. Use of design rationale will normally become a necessity to allow a better understanding of the knowledge. Consequently, there is a need of principles and methods to enable capture, structure, and access design rationale. In this study, a framework for modeling design knowledge and managing design rationale in order to support maintenance of design automation systems is presented. Managing of design rationale concerns enabling capture, structure, and access to design rationale. In order to evaluate the applicability of the framework, the findings are tested through design automation systems in two case companies. / Impact / Adapt

As the markets’ needs change rapidly, developing a variety of products that meet customers’ diverse needs is a competitive factor for many manufacturing companies. Development of highly customized products requires following an engineer-to-order business process to allow the products to be modified or adapted to new customers’ specifications, which brings more value to the customer and profit to the company. The design of a new product variant involves a large amount of repetitive and time-consuming tasks but also information handling activities that are sometimes beyond human capabilities. Such work that does not rely so much on creativity can be carried out more efficiently by applying design automation systems. Design automation stands out as an effective means of cutting costs and lead time for a range of well-defined design activities and is mainly considered as a computer-based tool that processes and manipulates the design information. Variant design usually concern generating a new variant of a basic design, that has been developed and proved previously, according to new customer’s demands. To efficiently generate a new variant, a deep understanding of the intention and fundamentals of the design is essential and can be achieved through access to design rationale—the explanation of the reasons and justifications behind the design. The maintenance of product families and their corresponding design automation systems is essential to retaining their usefulness over time and adapting them to new circumstances. Examples of new circumstances can include the introduction of new variants of existing products, changes in design rules to meet new standards or legislations, or changes in technology. To maintain a design automation system, updating the design knowledge (e.g. design rules) is required. The use of design rationale will normally become a necessity for allowing a better understanding of the knowledge. Consequently, there is a need for principles and methods that enable the capture and structure of the design rationale and sharing them with the users. This study presents methods and tools for modeling design knowledge and managing design rationale in order to support the utilization and maintenance of design automation systems. Managing design rationale concerns enabling the capturing, structuring, and sharing of design rationale. The results have been evaluated through design automation systems in two case companies. / Att kunna erbjuda kundanpassade produkter har blivit allt viktigare för många tillverkande företag. Utformningen av en ny produktvariant involverar en stor mängd repetitiva och tidskrävande uppgifter men även informationshanteringsaktiviteter som ibland är bortom mänskliga möjligheter. Sådant arbete som inte förlitar sig så mycket på kreativitet kan genomföras mer effektivt genom att använda designautomatiseringssystem. Designautomatisering framstår som ett effektivt sätt att minska kostnader och ledtid för en rad väldefinierade designaktiviteter och betraktas huvudsakligen som ett datorbaserat verktyg som analyserar och syntetiserar designinformationen. Variantdesign handlar vanligtvis om att skapa en ny variant av en grundläggande design, som har utvecklats och bevisats tidigare enligt nya kunders krav. För att effektivt skapa en ny variant är en djup förståelse för designens avsikt och grundläggande uppbyggnad avgörande och kan uppnås genom tillgång till ”design rationale”- förklaringen av skälen och motiveringarna bakom designen. Underhållet av produktfamiljer och deras motsvarande designautomatiseringssystem är viktigt för att behålla användbarheten över tid och anpassa dem till nya omständigheter. Exempel på nya omständigheter kan innefatta införande av nya varianter av befintliga produkter, ändringar av designregler för att uppfylla nya standarder, lagstiftningar eller tekniska ändringar. För att upprätthålla ett designautomatiseringssystem krävs uppdatering av designkunskapen (t ex designregler). Användningen av design rationale kommer normalt att bli en nödvändighet för att ge en bättre förståelse av kunskapen. Följaktligen finns det ett behov av principer och metoder som möjliggör fångande och strukturering av design rationale och dela dem med användarna. Denna studie presenterar metoder och verktyg för modellering av designkunskap och hantering av design rationale för att stödja utnyttjande och underhåll av designautomatiseringssystem. Vid hantering av design rationale gäller det att göra det möjligt att fånga, strukturera och dela med sig av design rationale. Resultaten har utvärderats genom att undersöka effekterna av dem i designautomationssystem i två företag.