Product-service systems (PSS), or value propositions, are foreseen to bring about challenges in product development. Traditionally, engineers normally manage tangible elements in relation to products, and are lacking approaches to deal with the intangibles incorporated in PSS development. The purpose of the paper is to elaborate on and propose a framework for value assessment and a simulation approach. Conceptual examples are used to discuss the proposed framework, and a contribution of the paper is that it exemplifies the reasons why intangible value have to be addressed more directly in industry in general and in PSS in particular.