A knowledge-level model for concurrent design.

The concurrent approach to engineering design, concurrent design, implies that expert knowledge regarding a number of different downstream life-cycle perspectives (such as assembly, manufacture, maintainability etc) should all be considered at the design stage of a product's life-cycle. Extensive and valuable work has been done in developing computer aids to both the design and concurrent design processes. However, a criticism of such tools is that their development has been driven by computational considerations and that the tools are not based on a generally accepted model of the design process. Different models of design have been developed that fall into a number of paradigms, including cognitive and knowledge-level models. However, while there is no generally accepted cognitive model describing the way designers and design teams think, the concept of the knowledge-level has enabled a more pragmatic approach to be taken to the development of models of problem-solving activity.Different researchers have developed knowledge-level models for the design process, particularly as part of the CommonKADS methodology (one of the principal knowledge-based system development methodologies currently in use). These design models have significantly extended design thinking in this area. However, the models do not explicitly support the concurrent design process. I have developed top-down knowledge-level models of the concurrent design process by analysis of published research and discussions with academics. However some researchers have criticised models for design that are not based on analysis of 'real-life' design. Hence I wished to validate my top-down models by analysing how concurrent design actually occurs in a real-life industrial setting.Analysing concurrent design activity is a complex process and there are no definitive methodological guidelines as to the 'right way' to do it. Therefore I have developed and utilised a novel method of knowledge elicitation and analysis to develop 'bottom-up' models for concurrent design. This is based on a number of different approaches and was done in collaboration with a number of different design teams and organisations who are engaged in the concurrent design of mechanically based products.My resulting knowledge-level models are an original contribution to knowledge. They suggest that the concurrent design process consists of a number of discrete sub-tasks of propose, critique and negotiate. These models have been instantiated as generic model templates, using the modelling formalisms specified by CommonYADS. These models have been implemented on a software tool, the CommonKADS workbench, in order to provide support for developers of computer-based systems for concurrent design.