Dissertation (PhD)--University of Stellenbosch, 2007. / ENGLISH ABSTRACT: The globalisation is increasing the complexity of product development in terms of product variants and the range of technologies implemented. It emphasises the requirement for developing various design information support systems for the world market. However, small and medium enterprises that employ a wide range of design procedures may not be able to afford customised information support systems, with the result that there is a need for flexible, i.e. easily adaptable, design support tools. Four case studies were carried out to investigate the requirements for an information support system aimed at the design process and design documents. They indicated that a design information support system aimed at supporting design teams in the pre-detail mechanical design phases should be able to adapt various design methods and handle design information in a flexible way. Flexible here means being applicable over a wide range of contexts and extendable without affecting data already captured. Ontology based approaches are widely applied where diverse information has to be handled. The development of the Internet today also makes a distributed design approach more and more popular for mechanical design. An internet-based design support system called DiDeas II (Distributed Design assistant) was developed here with an ontologybased approach implemented to provide distributed and flexible assistance during concept generation in small companies. The DiDeas II has separate server side and client side programs, which communicate through a TCP/IP connection. DiDeas II allows design teams to manage their design information according to various design methods, to decrease time-delays and to improve communication between team members. These benefits were confirmed in two case studies carried out to evaluate DiDeas II. Keywords: Distributed design; ontology; concept design, web-based system. / AFRIKAANSE OPSOMMING: Globalisering verhoog die kompleksiteit van produkontwikkeling, in terme van produk variante en die bereik van tegnologieë wat geïmplementeer word. Dit beklemtoon die behoefte om verskeie ontwerp-inligting-ondersteuningstelsels vir die wêreldmark te ontwikkel. Klein en medium ondernemings wat 'n wye spektrum ontwerpsprosedures gebruik, kan egter nie doelgemaakte inligting-ondersteuningstelsels bekostig nie, met die gevolg dat daar 'n behoefte vir maklik-aanpasbare ontwerp ondersteuningstelsels is. Vier gevallestudies is uitgevoer om die vereistes vir 'n inligting-ondersteuningstelsel gemik op die ontwerpproses en ontwerp dokumente, te ondersoek. Dit het aangetoon dat 'n ontwerp-inligting-ondersteuningstelsel, wat ontwerpspanne in die voor-detail meganiese ontwerp fases moet ondersteun, by verskeie ontwerpmetodes moet kan aanpas en ontwerpsinligting op 'n aanpasbare manier kan hanteer. Aanpasbaarheid in hierdie konteks beteken toepaslik oor 'n wye spektrum kontekste en uitbreibaar sonder om data wat alreeds ingevoer is, te beïnvloed. Ontologie-gebaseerde benaderings word wyd toegepas waar diverse inligting hanteer moet word. Die ontwikkeling van die Internet maak 'n verspreide-ontwerpbenadering meer en meer gewild vir meganiese ontwerp. 'n Internet-gebaseerde ontwerpondersteuningstelstel genaamd DiDeas II (Distributed Design assistant) is hier ontwikkel met 'n ontologie-gebaseerde benadering wat daarop gemik is om verspreide, aanpasbare hulp te verleen aan klein maatskappye gedurende konsep- ontwikkeling. Die DiDeas II stelsel het afsonderlike bediener en kliënt programme wat deur 'n TCP/IP verbinding kommunikeer. DiDeas II laat ontwerpspanne toe om hulle ontwerp inligting volgens verskeie ontwerpmetodes te bestuur, tydvertragings te verminder en om kommunikasie tussen spanlede te verbeter. Hierdie voordele is bevestig in twee gevallestudies wat uitgevoer is om DiDeas II te evalueer. Sleutelwoorde: Verspreide ontwerp; ontologie; konsepontwerp; web-gebaseerde stelsel.