The concept of sustainable product-service systems has emerged recently, and is distinct from the ideas of cleaner production, eco-design and design for the environment. The concept goes beyond the environmental optimisation of products and processes and requires radical and creative thinking to reduce environmental impacts by a factor of between four and 20 times while maintaining an acceptable quality of service. Sustainable product-services consider alternative socio-technical systems that can provide the essential end-use function, such as warmth or mobility, that an existing product offers. Four types are outlined—result services; shared utilisation services; product-life extension services; and demand side management. Sustainable prod...