In early design stages, firms need to generate and assess their value propositions. Although both business developers and systems engineers capture customers’ needs to design the value proposition, they suffer from inefficient business and engineering processes interactions. Moreover, they lack methods to elicit the needs in a structured way and to explore the best value propositions. We propose to extend the affordance-based design for systems and services in order support the elicitation and capture of stakeholders’values; and to identify boundaries of the system design problem to explore the best value propositions. Hence, affordances — which describe what system provides to other systems and stakeholders — help to frame the context. Today, affordance-based design is mainly used for artifact design. We propose to extend this approach to systems and services and complement it with a focus on stakeholders’ activities and external systems’ stages. With regard to the different system design perimeters defined by affordances, value propositions are designed. The proposed method is illustrated on an AIRBUS Defence & Space innovative project.