Design for low-volume production
In high-volume products, costly investment in design and development is spread over a large production quantity. The result is high-quality, low-cost engineering. In contrast, products produced in low volumes (batch sizes of less than 50 units) often appear to offer inferior value for money.
This thesis describes the development of a design theory for economic low-volume production. The focus of the research is on identifying design techniques which reduce the cost while maintaining or improving the functional and aesthetic qualities.
Research into three design case histories of low-volume rehabilitation products for disabled users has supported the development of the method. Four re-designs covering seven different configurations have been analysed.
The research suggests that the level of value in a low-volume product is linked to the proportion of "Pre-packaged technology" it contains. Pre-packaged technology is high-volume systems, assemblies, components, materials, information or techniques which are subsequently incorporated into a low-volume product. Thus, in order to minimise cost in a low-volume product, the proportion of pre-packaged technology should be maximised.
A series of re-design tactics have been identified and linked into a coherent strategy which provides a "design for low-volume production" method. This is intended to support the re-design of a prototype into a product suited for low-volume production.
The re-design method has been tested in two case studies. The method was used to assess the scope for cost reduction in a product and then suggest design changes to reduce the cost. Results showed that the method contributed to cost reductions of over 25% whilst maintaining the level of function and appearance.
Design-led component selection charts have also been developed to support the selection of bought-in components for use in low-volume products. Charts for electrical energy sources and rolling element bearings are described.