Supplier involvement in NPD: A quasi-experiment at Unilever

Growing technological complexity makes it impossible for individual firms to be updated on all technologies relevant to new product development (NPD). Involving suppliers, who have knowledge of complementary technologies, in the early phases of NPD is therefore quite a common practice. However, the timing of involvement presents a management challenge. We explore how task ambiguity pertaining to NPD affects buyer-supplier interaction. We set up a quasi-experimental study, manipulating causal ambiguity to observe how this impacts buyer-supplier interactions over time. Our findings reveal that causal ambiguity influences the role expectations and resource mobilisation of the suppliers before interaction, the actors' mobilisation and their pattern of interaction, and the transformation of outcome and mobilisation of resources ex post interaction. We discuss the implications for managers and researchers in a buyer-supplier context.