In order to shorten the manufacturing time for new products and their moulds, the use and the development of modern techniques are critical. One of such technologies is the rapid prototyping method, which enables the designer and the costumer to see the physical presentation of new product which will be ready for marketing in the period of 3-6 months, already at the early stage of its development. During this period of 3-6 months, the mould must be manufactured and the product must be placed to the market. In this comprehensive R&D work, modern computer techniques must be applied. With the help of computer aided numerical simulations, solving of the greater part of the problems that can emerge during the product and/or mould manufacturing can be predicted. This paper is a result of the co-operation among three Slovenian companies in the development of new products. It starts with the rapid prototyping and computer simulations in the development phase of the product. The same CAE approach will be used in the implementation of modern mould manufacturing techniques, the whole development of the products being treated as an industrial implementation of concurrent engineering methods.