This paper describes cost modelling research, industrial approaches and commercial systems and how these relate to whole-life cost estimating. The particular focus of the research described is the applicability of current approaches for the modelling of low-volume, infrequent products, such as complex electronic systems at the conceptual design stage. Traditional approaches, in particular those used to predict costs for mechanical systems, are described in detail, and the approach by which cost estimating relationships are ascertained is summarized. The approaches used within sectors such as aerospace, construction and injection moulding are discussed and evaluated. All of these are placed in the context of the design process, and in particular their relationship to the conceptual design of a product is described. Finally, a review of commercial systems and the methods they adopt and domains to which they are applicable are described. The use of these approaches in terms of whole-life cost of a product is then mapped.